What is the way to quit the sin of homosexuality and return to Allah, after years of practicing it and regretting it?

You must initiate sincere repentance from the sin by immediately ceasing it, resolving not to return to it, and regretting what has passed. If these conditions are met, the repentance is valid. No matter how great the sin, Allah's mercy is vast, and the servant should have a good opinion of Allah, turn to Him, and trust that He will accept their repentance.

One must also strive for righteousness, which includes staying away from those who cause one to fall into evil, associating with good and righteous people, and diligently engaging in remembrance (dhikr) and supplication for steadfastness, for hearts are in Allah's hands. Furthermore, one must strive in obedience and increase in acts of worship, for "indeed, good deeds do away with ill deeds."