Switch off the main breaker.
Strip 1/2 inch of insulation from the ends of the white, black and red wires of the new circuit.
Locate the ground and neutral bus. It will be a metal strip with holes and screws in it, with bare and white wires connected to the holes. Locate two empty holes and loosen their corresponding screws with the screwdriver.
Insert the bare wire of the new circuit into one of the holes. Tighten the screw to secure it. Insert the white wire into the other hole, and tighten the screw to secure it.
Loosen both screw terminals in the new breaker. Insert the black wire into one terminal and tighten the screw to secure it. Insert the red wire into the other terminal and tighten the screw to secure it.
Fold the excess wire back into the box. Reinstall the panel cover.