To avoid inhaling drywall particulates, consider wearing a safety mask. Glasses or goggles will also help keep particles out of the eyes.
10 steps on 'How to Fix a Hole in the Wall'
Make a square over the hole
Measure the hole and make a square pattern that covers it. Cut the square using your construction cutter or drywall saw. This will make the patching a lot easier than cutting circularly.
Install the plywood
Cut the plywood to the appropriate measure of the square hole (don’t forget to add a 1-inch allowance on the left and right side of the square). Start a screw in the plywood so you can hang on to it while installing. Use at least a couple screws to hold the plywood in position and remove the starter screw after.
Cut your new drywall
Make an identical square cut of your new drywall that fits the hole. Screw it to the plywood to hold it in place.
Tape the edges
Use the mesh tape to cover the edges of the drywall patch.
Apply the first coat of compound
Mix the compound into a thick consistency. Use your drywall knife to apply the compound. Cover the mesh tape with the compound and make sure there are no air pockets.
Apply a second coat
Allow the first coat to set and mix another batch of the compound. Once done, feather out the edges and make the application as smooth as possible. Try your best to match the smoothness of the undamaged drywall.
Apply a final coat
Smooth the edges to perfection by applying a final coat. Check if the contour is consistent with other parts of the drywall and that it feathers seamlessly.
Sand the patch
Use the sandpaper to smooth down the drywall patch. Level protruding particles in the hardened compound to make it blend nicely.
Prime the patch
Apply a primer prior to painting. This will make the final paint job look nicer.
Paint the patch
Apply your desired paint color to the primed patch and paint evenly.