Is it permissible to draw a part of a human, such as the face, and if drawing is unlawful, must one dispose of the drawings, and does sincere repentance save one from the warning that "painters will be among those most tormented on the Day of Resurrection," and what should one do with their previous drawings, especially large wall murals?

All praise is due to Allah for guiding you to repent from drawing living beings. We have previously explained the prohibition of such drawings. As for drawing a part of a picture, such as the head, or the face, or the rest of the body without the head, there is no harm in it. This is because removing a part without which life cannot exist takes it out of the ruling of prohibition. However, it is more pious to avoid it. And part of perfecting repentance is to dispose of what you have drawn of living beings by effacing them and not keeping them. You may ask the school administration to cut off a part of the picture. If they do not respond or if it is difficult for you, then there is no blame upon you.