Installing a door knob can be as simple as removing a few screws to take out the old knob and putting in the new one. However, if the openings for the knob, face plate or strike plate need to be changed, the process is more difficult.
The first step is to remove the screws that hold the old knob in place. If the screws are hidden under the cover plate, look for a slot with a small metal piece on the side of the handle. Push the metal piece in to release the knob and reveal the screws. Remove the screws that hold the knob, and then remove the screws that hold the old latch mechanism. Remove the old strike plate from the door jamb, if necessary.
Check to see how the new knob fits the old opening. Many knobs are adjustable to different backsets, or the distance from the center of the knob to the edge of the door. If necessary, use a power drill with a hole cutter to change the backset. Use a hammer and chisel to adjust the size of the latch faceplate and strike plate openings in the door and door jamb, if necessary.
To install the new knob, push the latch mechanism into place, taking care that the curved side of the striker faces the strike plate. Next, put the new knob through the opening, being careful not to strip the screws. Check if the new knob latches and locks properly.