Remove the door knob and hardware using the screwdriver. This is easiest to do when the door is open. Set the door knob and hardware aside, as they will be re-installed later.
Remove the screws that attach the door hinge to the door, starting with the bottom hinge and working your way to the top.
Carefully lay the door on the saw horses.
Put on the breathing mask to protect from dust particles.
Sand all surfaces of the door, using the electric orbital palm sander with 120-grit sandpaper.
Wipe the paint dust from the door surfaces with either a large sponge or rag.
Evenly apply a coat of paint to the door and the door edges and allow to dry as indicated on paint packaging.
Flip the door over and paint the opposite side, as done in Step 7.
Apply additional coats of paint as indicated on paint packaging, and allow the paint to completely dry.
Re-install the door knob and hardware that was removed.
Mount the door back on the door hinges, starting with the top hinge and working your way down to the bottom.