Remove the screws that hold the protective ring in place, if there is one. Some rings are pressed into place and are removed by gently sliding the flat blade of the screwdriver under the edge and prying upward.
Locate the screws holding the door knob together on the inside of the door. Remove the screws with the appropriate screwdriver. Pull the two halves of the knob apart.
Remove the small screws holding the plate and latch mechanism in place. Pull out the latch.
Insert the new latch into the edge of the door with the beveled edge of the mechanism facing the interior of the house. Make certain the plate is flush with the door edge. If you install the mechanism upside down, the lock will not work properly. Cover the mechanism with the face plate and secure it with the screws provided by the manufacturer.
Push the exterior part of the door knob - the part with no screw holes - into the lock hole. Line up the through-bolt of the door knob with the fabricated hole in the lock bolt. Generally, there are two or more holes in the lock bolt to standardize the fit of the lock into a variety of doors. Choose the hole with the tightest fit for the knob.
Insert the interior part of the door knob into place. Push the two parts of the door lock together. Screw the door knob into place with the long screws provided with the lock set. Replace the strike plate on the door jamb with the new strike plate in the lock set. Test the new lock for a proper fit and a secure the locking mechanism.