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.
6. Cut a piece of drywall tape to the length needed with a utility knife. Press the tape into the mud with your fingers. Complete the joint by gently pressing the tape into the mud repeatedly with the drywall knife until it lies flat and is covered with a thin layer of mud.