Examine the Door Jamb Closely examine the door jamb and determine if it is solid. There should be no cracks, holes or brittle wood from rot. If everything looks good, you can proceed with just replacing the door, rather than the door and the door frame.
Remove the Door Start by removing screws from the hinges attached to the door. Once the door is detached from the hinges, remove it from the entryway. The door should be set aside if it is in good condition and fits well in the door frame to be used as a template to cut the new door later. Then, remove the screws from the hinges and take them off the jamb too.
Address the Threshold Unscrew the threshold across the floor where the door will be replaced. If the old door threshold is connected to the door jamb and cannot be easily removed under the siding, you can use a reciprocating saw or oscillating tool to cut and remove it. If your threshold is solid and in good condition, you can leave it in place and install the door. The area under your threshold will have seen the most moisture. Ensure the wood in this area is solid and free from rot. Inspect the full frame and jamb to ensure they are intact. There should be no cracks, dry rot, splits or gouges that will weaken the frame.
Install New Hinges (Optional) With the door separated from the pre-hung frame, if you want to use different hinges, lay it on sawhorses and install new hinges. Again, verify that the placement of the hinges on the door will line up with the location of the hinges in the door jamb. Only change the door hinges if you want to change the metal finish from the color installed at manufacturing.
Install Exterior Door With the new door still lying on the sawhorses, gently lay the old door with the handle and door sweep removed on top of it. Line up the hinges and handle holes, and trace the shape of the old door on the new one. Depending on how much needs to be removed, cut the new door to match using a circular saw, belt sander, or power planer. In many cases, especially in newer homes, very little to nothing will need to be removed. Line up hinges on the door to the door frame opening and screw the door into place. Use door jacks or shims to help hold the door in place while securing it with screws. Start with the middle hinge and then work top to bottom with the other two hinges. Once screws have been secured, test the door swing. Ensure the door swings freely and without rubbing anywhere on the jamb.
Install New Threshold If installing a new threshold, do a dry fit to ensure your threshold will allow the new door to open and close freely before securing it. Apply construction adhesive and screw into place with provided screws. Note: Some thresholds are high-profile, and others are designed with a low profile. The goal is not to have a large gap at the bottom of the door, which will allow drafts and moisture to enter
Install Doorknob and Deadbolt Verify that the door handle and deadbolt will line up with the strike plate location. Remove the old strike plate for the handle and deadbolt and replace it with new ones to match the new metal finish of the door handle and deadbolt. Install the handle and deadbolt and confirm that the door locks securely. You may have to slightly adjust the placement of the strike plate to get a solid engagement with the handle and deadbolt. If the strike plate for the handle and deadbolt does not align, drill and chisel out new strike plate holes. Then, use Bondo to fill in the old holes, sand them back, and then paint the door frame.
Install Weather Stripping Upon completion of the door installation, verify that the door swings smoothly and that the handle and deadbolt are locked securely. Install weather stripping on the exterior of the door. If re-installing the old weather stripping, it should go right back in place. If replacement weather stripping is used, it is highly unlikely the new holes will line up with the old holes. Ensure all holes have been covered and not exposed to moisture over time. If screw holes are exposed, fill with Bondo, sand back and repaint.
