What is the proper way to erase forbidden images?

Praise be to Allah.

The image is the face, which must be erased so that the image disappears, because the Prophet (peace and blessings of Allah be upon him) forbade striking the “image”. (Narrated by al-Bukhaari).

 The meaning is that it is forbidden to strike the face, as was explained in other ahaadeeth. The fact that “image” means the face means that the facial features must be erased. And Allah knows best.