This story shows how to install a prehung exterior door.
An exterior door is heavy, so have it delivered unless you have a truck, and enlist one or two assistants to help you move it into place.
You may need to wait a week or two for delivery of the door that's just right for you. Measure the width of an existing doorjamb or measure the thickness of your rough opening to be sure the jamb is the correct width for your wall; the front interior jamb edges should be flush with your drywall or plaster.
Many prehungs come with brick molding for the exterior, but you may choose to install your own moldings.
Start with a rough opening that is correctly sized and reasonably square, level, and plumb.
About 4 hours to install a door with standard trim inside and out
Tape measure, drill, hammer, level, tin snips, chisel, circular saw, stapler, caulk gun, screwdriver, nail set, reciprocating saw, utility knife
Basic finish carpentry skills
Frame the rough opening or remove an existing door and prepare the rough opening.
Prehung exterior door, metal drip edge, exterior brick molding, interior casing, casing nails, finishing nails, composite shims, exterior caulk, wood filler, fiberglass or foam insulation