Replacing Interior Doors
 

My hubby does it all the time. I think the main thing is make sure you get the correct size when you measure. The door comes complete with frame and when installing be very carefull to keep the frame intact.Kaulking all cracks when finished.

Make sure you get them install them opening in the direction you want. It may sound obvious, but it's one of those little things some husbands overlook until it's too late...

You got to get the correct dimensions of your doors.Keep in mind that a door needs space all around it to open and close properly even when the wood swells and contracts with seasonal/humidity changes.

This is how I fitted new interior doors. It is easier with two people, unless you're six feet tall, flexible and strong. :D

After ensuring you have the correct size replacement door, and removing the original, you need to ensure that all the screw holes on the door and the frame are aligned, by holding the door against the frame and marking both for screws,you will probably have to chisel out the rebate for the hinges placement.
Affix the new, correct type of hinges to the door, re-check the placement of the hinges, then screw the door to the frame. Do not tighten these screws completely until you have checked that the door hangs properly. It is best to use a hand screwdriver for this part, so you don't overtighten the screws.