To fix a big hole we are going to start by cutting out the damaged drywall, using the keyhole saw going outwards until you reach the 2x4 called stud, with the utility knife cut the left and right edges vertically over the outer studs about 3/4", this should be about half the width of the wood exposed.Measure the opening size of the hole with the measuring tape to cut a piece of drywall to match the opening size, or slightly smaller, is very important not to forget that the measuring starts from the 3/4" overlap on the studs, to secure it in place use some drywall screws, or you can also use drywall nails if you wish.
The procedure is the same as if you were patching a small hole, so instead of putting the instructions all over again just follow the link that says drywall hole repair.
To watch the video the link is fixing drywall (video)
