Re: Replacing outside door molding
some doors are built and installed differently than others.
in some cases the door is set plumb by nailing through the brick mold into the framing, others are done by shimming and driving nails or screws through the jamb into the jack studs.
if its the latter, all you need to do is gently pull off the old trim and replace it with new trim that matches the width of the old so it meets the siding, even allow for a 1/8" gap for caulking to go in. before nailing it on set it into a bead of caulking both along the wall of the house and the edge of the jamb so to create a proper seal,
if it was installed via nails through the brick mold, you shoulld pull off the existing interior trim so to install shims then drive screws though the jamb to lock it in place. from there remove the brick mold and install new trim
fire up the saw and make some dust