How to Replace the Assembly on Bathroom Knobs

Out With the Old

• 1

  Find the screw heads that hold the door knob in place. For most bathroom doors, these will be on the same side as the lock switch.

• 2

  Unscrew the screw heads using your screwdriver. You can use a power drill or power screwdriver for this if you have an extension bit that keeps the drill or driver from bumping into the door knob.

• 3

  Pull the door knob away from the door on both sides. With the screw heads removed, this should be easy. If it's stuck with paint or stain, rap it once with the butt of your screwdriver.

• 4

  Pull the lock mechanism out of the door through the hole in the door's edge. If your door has a metal plate attached to the edge, remove it using your screwdriver.

• 5

  Measure the distance between the edge of your door and the centerline of the hole where your doorknob used to be. This distance is the "backset." You will need to buy a replacement assembly that's compatible with that backset measurement.

In With the New

• 6

  Slide the new assembly into the door through the hole in the edge. Confirm that it's facing the right direction -- with the angled part of the bolt facing away from the bathroom.

• 7

  Set the door knob components back in place on either side of the door. For most assemblies, you can use the same knobs you had before, or brand new ones that come with the assembly -- often at a price comparable to buying the assembly by itself.

• 8

  Slide the screws into position, then tighten them in place with your screwdriver.