Duke William of Normandy won the battle because was well prepared and had a good army. They prepared carefully for the battle. The Normans had knights on horseback who were skilful fighters.
A utility knife, metal ruler, and a hammer can be faster than trying to carefully saw an opening. Score the drywall a couple times till you are most of the way through, then just knock a hole with the hammer and break the drywall back at the score lines.
Apply drywall joint compound to any holes or cracks in the ceiling, using the putty knife. Use the edge of the putty knife to scoop a portion of joint compound from the container. Apply a thin, smooth layer of compound over the damaged area. Use scissors to cut a piece of mesh drywall tape to fit.