At the end of the Lotus Sutra is a Bonus chapter which ties everything together and tells you how to awaken your Buddha nature called “Sutra on How to Practice Meditation on Bodhisattva Universal Worthy”. Here are some extracts from it in BOLD.
It begins with three monks, Ananda, Mahakashyapa and Maitreya asking the Buddha how they can achieve this enlightenment …
“World-Honored One, after the thus come one has entered extinction, how can living beings nurture the bodhisattva mind, practise the great vehicle broad and impartial sutra, and employ correct thoughts in pondering the realm of the single truth? How can they be certain of attaining the mind of unsurpassed enlightenment?
… in their everyday lives as ordinary people with desires and obstacles to overcome.
How, without cutting off earthly desires or separating themselves from the five desires, can they purify their senses and wipe away their offenses? How, with the pure everyday eyes they received from their fathers and mothers at birth, and without cutting off the five desires, will they be able to see what lies beyond obstacles?”
Shakyamuni tells them to listen carefully and explains that at Eagle Peak and other places he has given lots of explanations
The Buddha said to Ananda: “Listen with attention, listen with attention and consider the matter carefully. In the past I, the thus come one on Mount Gridhrakuta and in other places, have already widely explained in detail the way of the single truth.
But now he will explain the method for the benefit of everyone in the future
Now in this place, for the sake of living beings of ages to come who wish to practise the unsurpassed Law of the great vehicle, and who wish to study the practice of Universal Worthy and to carry out Universal Worthy’s practice, I will now explain the method that you should hold in mind.
It doesn’t matter if you have awoken to your own Buddha nature before or not, but if you do what I suggest you can reduce the effects of negative karma and will see your Buddha nature (and the Buddha nature of others)
Whether you have already seen Universal Worthy or have not seen him, I will now explain for you the steps to be observed in order to reduce the number of your offenses. … The benefits of this meditation remove obstacles and impediments so they can see the finest, the most wonderful forms.
You should repent for your past actions, study the Lotus Sutra, and respect others who respect the Lotus Sutra. You should see everyone as a buddha and recognize that we are all one family.
“…he should pay obeisance to the buddhas of the ten directions, practice the method of repentance, read the great vehicle sutra, recite the great vehicle sutra, ponder the meaning of the great vehicle, keep in mind the concerns of the great vehicle, and reverently offer alms to those who uphold the great vehicle. He should view all people with the thought that they are buddhas, and all living beings with the thought that they are his father and mother.”
How can we repent? We just need to chant "Nam-myoho-renge-kyo" and we will awaken our Buddhahood and overcome all of our negative karma.
The Buddha said to Ananda, “After the Buddha has passed into extinction, if the disciples of the Buddha wish to repent their evil and undesirable acts, they should simply recite and read the great vehicle sutra. … If a person recites and reads the great vehicle broad and impartial sutra, one should know that such a person is endowed with a buddha’s benefits. All his evils wiped out forever, he is born from the Buddha wisdom.”
Shakyamuni is now going to explain how to change our karma / fundamental darkness in different ways.
At that time the world-honored one spoke in verse form, saying:
We need to purify our eyes, to see the truth of the way the world works, to see our true nature and to appreciate the beauty around us. We do this by chanting "Nam-myoho-renge-kyo".
If there are evils in the eye organ,
If karma impedes the eye and the eye is impure
Simply recite the great vehicle,
Keep in thoughts the highest principle.
This is called repentance of the eye,
Which wipes out all undesirable acts.
We need to purify our ears, to clearly hear and perceive the lies or deceit of others, and to recognise the inner voice inside of us that tries to deceive us. We do this by chanting "Nam-myoho-renge-kyo" and reflecting on the true nature of phenomena.
If the ear organ hears confused sounds
This will injure and confuse the principle of harmony.
From this arises madness of the mind
And one will behave like a foolish monkey.
One should constantly recite the great vehicle,
Meditate on how phenomena are empty and without aspect,
Wipe out all evils forever,
And with heavenly ears listen to the ten directions.
A little bit strange this one, but we need to purify our nose so that it doesn’t deceive us or lead us astray in pursuit of things that seem sweet, but distract us from our mission. We do this by chanting "Nam-myoho-renge-kyo".
If the nose organ is attached to fragrant scents,
Their stain will give rise to sensations.
When the nose is maddened and deranged in this manner,
The stain of it will produce various kinds of dust.
But if one recites the great vehicle sutra
And meditates on the truth of phenomena,
One will be released from all evil karma forever
And in future existences will produce it no more.
This is another of the big ones. We need to purify our tongue so that it doesn’t lead us astray with gossip, rumours, slander, etc. Funnily enough, this one doesn’t require us to chant "Nam-myoho-renge-kyo"!! We just need to speak positively with compassion, tranquillity and without discrimination.
The tongue organ gives rise to the undesirable acts
Of the five types of evil speaking.
If one wishes to control and tame it,
One must diligently practise pity and compassion.
Ponder the principle of the true tranquillity of phenomena,
Do away with discriminatory conceptions.
We need to calm our minds, especially when they are troubled with doubts, concerns, or mischievous thoughts. We do this by chanting "Nam-myoho-renge-kyo" and focussing on the Buddha’s body.
The mind organ is like a monkey,
Never still for an instant.
If one wishes to master and subdue it,
One must diligently recite the great vehicle.
Keep in mind the Buddha’s great enlightenment body,
All the power and fearlessness he has won.
Our lives and mind are changeable and easily influenced
The body, this master of motions,
Is blown about like dust in the wind.
The six thieves sport and play with it,
Free from all hindrance or restraint.
To erase this fundamental darkness and create a state of Buddhahood, chant "Nam-myoho-renge-kyo".
If one wishes to wipe out these evils
And be free forever from the burden of their dust,
To dwell constantly in the citadel of nirvana
Peaceful in mind, calm and placid,
Then recite the great vehicle sutra,
Keep in mind the mother of bodhisattvas.
When we chant and reflect on the Mystic Law we can see where our negative karma has come from.
Immeasurable numbers of excellent expedient means
Arise from pondering the true aspect.
Phenomena such as these six
Are called the six sense organs.
All the entire sea of karmic impediments
Is born from deluded thoughts.
To expediate negative karma, sit and chant "Nam-myoho-renge-kyo"
If one wishes to carry out repentance,
Sit upright and ponder the true aspect.
Then the host of sins, like frost or dew, can be wiped out by the sun of wisdom.
Therefore with the utmost power of one’s mind
One must carry out this repentance of the six sense organs.
Now you know what to do, do it and teach others to do it.
When the Buddha had finished speaking these verses, he said to Ananda: “Now you must take this repentance of the six sense organs and the method for meditation on Bodhisattva Universal Worthy and, observing the proper distinctions, preach them far and wide to all the heavenly and human beings of the ten directions everywhere.
All extracts are taken from pages 369 – 396 of Burton Watson’s “The Lotus Sutra and Its Opening and Closing Sutras”