The first time a homeowner attempts to replace a doorknob, they usually find the process a bit confusing. Taking a doorknob off, however, is usually a fairly straightforward process, especially if the doorknob has exposed screws. It does get a little more complicated when the doorknob has hidden screws, but once you're aware of a few tricks, removing a doorknob with hidden screws really isn't all that hard.
Locate a small slot or hole (called a detent) on the shank of the doorknob. Using a narrow-bladed screwdriver, push the tip of the screwdriver into the detent. Pull on the doorknob, giving it a small twist, until the doorknob comes off.
Use the narrow-bladed screwdriver to remove the trim ring (also called a decorative plate) by inserting the screwdriver into the notch on the ring to loosen it from the door. The notch is usually located at the bottom of the ring, but depending on how it was installed, you may find it located anywhere around the doorknob.
If the trim ring does not have a notch, pry it away from the door at the bottom of the ring using the narrow-bladed screwdriver. This will help to hide any scratches or you may have made, since they won't be as visible once you have the new doorknob in place.
Find the two long screws keeping the clamping plate (the metal piece still on the door) in place and remove them using the regular screwdriver. Take the actuating shaft assembly out of the door along with the remaining half of the doorknob from the opposite side of the door.
Remove the screws from the faceplate (metal plate on the edge of the door) with the regular screwdriver, then take out the latch assembly. You are now ready to install a new doorknob in your door.