How to Paint a Door Video
If you need to paint a new wood door or an existing interior door, and want long lasting, professional results, remove all door hardware first. The time spent trying to mask off all the hardware will be longer than simply removing it. Plus, you won't get paint on the door knob or plates.
Remove the door knobs and back plates first. Remove the lock set and don't forget the hinges. To help with the hinge removal, open the door slightly and place a shim under the corner to support the door. Then unscrew the hinges, starting with the bottom and working your way up. Once the hinges have been removed, you can take the door down and lay it on the latch edge. This will allow access to the top, bottom and hinge edges. It is important to paint these edges so moisture does not get into the wooden door and cause it to warp or twist.
Once all the hardware is off, paint the door getting all the sides and edges. The removal of the hardware will help with that professional looking finish.