Install your siding according to the manufacturer’s instructions up to the point where you need to make cuts around the range vent. Use the tape measure to measure from your full pieces of siding up to the range vent, and mark those measurements on the piece of siding you need to cut. Mark the piece with the pencil and carpenter square.
Cut down wood siding with a circular saw. While the saw is unplugged, adjust the depth of the blade so that you are only cutting as deep as required by the thickness of the siding. Set the piece of siding up on scrap pieces of wood so you have a cutting space. Plug the saw in, pull the trigger and push the blade through the wood siding along your marks to cut the siding.
Cut down metal, vinyl, concrete fiber and composite siding with a pair of electric shears. In essence, these are an electric pair of scissors that you can hold in your main hand while you stabilize the piece of siding in your off hand. Push the electric shears into the siding and let the machine do the work while you guide the blades along your marks.