There are a few things you'll need to do before repairing your drywall: 1. Assess the damage and determine how much needs to be replaced. 2. Cut out the damaged section of drywall using a keyhole saw or jigsaw. 3. Score and snap the drywall to fit the hole (be careful not to cut yourself!). 4. Apply joint compound to the edges of the hole and attach the new drywall piece. 5. Smooth out the joint compound, then paint over it for a seamless finish.