There are a few basic steps you'll need to take in order to install an exterior door:1. Decide on the placement of your door. Doors should not be installed in areas that will be exposed to direct sunlight or rain, as this can cause the wood to warp and the sealant to break down prematurely. You'll also want to make sure that there is enough space on either side of the doorframe for it to swing open and closed without hitting anything.2. remove the old door if there is one currently in place. This can be done by prying off the trim around the doorframe with a crowbar, then removing the screws that hold the door in place.

1. Measure the height and width of the door opening. Add 1 inch to both the height and width to get the actual size of the door. 2. Order a door that is this size, or slightly larger if you want a buffer zone for weatherstripping or frame adjustments. 3. If you have trim around your door opening, remove it by prying it off with a crowbar or screwdriver. 4. Fit the new door into the opening, making sure that it is level horizontally and vertically. 5. Shimmy the top of the door until it is plumb (level) with the floor using shims placed between.