Prybar (like a Stanley Wonderbar)
Screw gun or Drill
Reciprocating saw with a bi-metal blade
Caulking & a Caulking gun
Nails, screws & fasteners
Measure the existing (old) frame to make sure the new doorframe will fit. Most doorframes come in standard sizes.
Remove the old threshold - this will probably require removing three or four screws and lifting the old threshold away.
Remove the hinge pins on the old door - pry them up & out with a hammer and screwdriver.
Remove the old door - the door can be very heavy, so don't do it by yourself if it's too heavy to lift alone.
Remove old door trim with a prybar and a hammer. Be careful not to damage the wall around the doorframe.
Detach the old Doorframe from the House- The doorframe will probably be nailed or attached to a 2x4 which is attached to the house. Use the reciprocating saw with a bi-metal blade (it'll cut through most anything) to saw round the perimeter of the old doorframe to separate it completely from the house. Make sure to wear safety goggles when operating the saw. Keep a tight grip on the reciprocating saw and be careful when sawing, because the saw may "buck' or "jump" when it hits some of those nails. You may have to remove brick trim from the exterior of the doorframe as well before you're ready to remove the doorframe.
Remove the old Doorframe - Give the frame a little kick to loosen it from the doorway; bring the two side pieces together as you lift the bottom of the frame out first. Discard the old doorframe.
Clean the opening - get rid of dirt, bugs, loose bits of wood, etc.
Measure the "rough opening" - that's the space between walls of the house once the old doorframe has been removed. The rough opening should be about " to " wider than the frame you're about to install. That extra room allows for proper placement and fine-tuning (with shims) of the new doorframe position before you attach it to the house.
Check the Level of the opening - If this opening's level, it will make the frame replacement much easier. If it's not level, you may have to add sand or soil, or scrape away excess dirt, to create a level opening for the new doorframe.
Place the new doorframe into rough position in the opening - the door & frame combination might easily weigh 100 pounds or more, so get help when you move it into position. We removed the door from the frame to make installation that much easier (just unscrew the three door hinges from the frame, and save the screws and hinges for reattachment later). Use a square (or your hand) to bring the hinged side of the frame flush up against the inside wall of the house.
Anchor the hinged side of the doorframe - use a screw gun to drill 3" screws through the area where the door hinges will be reattached and into the wall to anchor the hinged side of the frame. Use one 3" screw for each hinge opening for a total of (3) 3" screw to anchor the hinged side of the frame to the wall.
Prepare to Anchor the other side of the doorframe- the first step is to attach a drill bit to the screw gun to drill "pilot holes" into the wood on the opposite side of the doorframe. The 3" screw you inserted on the hinged side will never be seen because they'll be covered by the hinges that hold the door to the frame. The screws on the opposite side will be visible however. Drilling pilot holes lessens the chance of wood splitting when screws are inserted. Drill three pilot holes, each at a height that roughly matches the placement of the 3" screws on the other side of the frame.
Shim the Doorframe - Use shims on the unattached side of the doorframe (opposite the hinges) to tighten the fit between the doorframe and the wall. Insert a pair of shims (skinny end first) behind each pre-drilled pilot hole on either side of the gap between the frame and the house, and slowly push them towards one another until the fit is snug. Use the utility knife to "score" the part of the shims that protrudes beyond the frame and break off the ends with a hammer.
Double-Check the Level of the doorframe before attaching the other side to the house.
Anchor the other side of the doorframe - drill screws into the pilot holes through the shims and into the wall
Reattach the door to the frame - reattach the three hinges to the newly installed doorframe.
Test the "fit" of the door in the doorframe - open and close the door a few times to ensure you've reattached it properly and to confirm that the new doorframe fits the old opening properly.
Attach new trim to frame - most of these "pre-hung doorsets" come with pre-cut trim, so attach the trim around the frame.
Seal the frame to the house with caulk - make sure you have a god tight seal between the frame and the house with a generous application of caulk around the entire frame.
Install Lockset and Door hardware.
Prep door & frame for painting - the door we installed comes primed and ready for a coat of paint.