The phrase "drum in to" refers to the process of repeatedly instilling or teaching a particular idea or skill until it becomes ingrained. Some antonyms for this phrase might include "erase," "unlearn," "forget," "uninstruct," or "disperse." While "drumming in" involves repetition and reinforcement, these antonyms focus on the idea of undoing or reversing learning. For example, if you wanted to teach someone how to cook a particular dish, you might drum the recipe into them by going through the steps multiple times. On the other hand, if you needed to undo a bad habit, you might need to work to erase or unlearn the behavior.