While a circular hole up to approximately 1 1/4-inches can be drilled using a spade bit, any larger diameter hole will need a hole saw to accomplish the task. A hole saw is a steel cylinder with saw teeth edges that attach to a power drill and come in various diameters. Using a hole saw drill bit is a skill that anyone can master with very little practice.
Place the hole saw in the correct size arbor. This should be stated on the back of the hole saw packaging.
Check to insure that the centre bit extends approximately 3/8 of an inch past the saw edge if the saw has an adjustable centre bit. For centre bits with a flat side, arrange the flat side with the setscrew and tighten to secure the centre bit.
Secure the hole saw in the chuck of a power drill. You should use an electric corded drill, unless your cordless is 18 volts or higher in capacity, or the drill will not have enough power to fully power the hole saw operation.
Center the hole saw bit over the area you wish to drill.
Activate the drill and the hole saw assembly by squeezing the trigger on the power drill.
Drill until the hole is fully cut out and the inner circle of wood can be removed from the piece being drilled.
Take care that the area where you are drilling is free of plumbing pipes or electrical wires. A hole saw will easily cut into either. Hole saws of various sizes can be purchased at any hardware store or home improvement centre.