I am replacing some interior door knobs. After much trial and error I was able to get the existing handle off, however, the hole is to small for the the new door knob hardware? Any ideas, or do I have to now purchase a very big drill?
you need a hole saw to make the correct size hole. easiest way is to take a scrap piece of wood and make a hole in it with the hole saw. then clamp the piece with the hole in it centered over the too small hole to act as a guide for the hole saw. make sure it is centered over the existing hole or in the proper distance from the edge of the door for your knob. i would clamp another scrap on the opposite side of the door so when the hole saw goes through it wont splinter the other side.