Things You'll Need
Power drill with screwdriver attachment
Dexter doorknobs are manufactured by Schlage, a manufacturer of both home and commercial security products. Dexter doorknobs are constructed of two parts: an external knob mounted on the exterior door surface that may or may not have a keyhole; and an internal knob that contains the locking mechanism on such doors. Removal of a Dexter doorknob is a fairly simple project for the DIYer, and requires no special tools.
Scrape away any paint that may be covering either side of the Dexter doorknob, using a paint scraper. This will make it easier to remove the doorknob. Take care not to damage the door during the scraping.
Unlock the door if it is locked, and open it. Position yourself on the interior side of the doorknob. This side of the knob will have two screws visible on the flange under the handle.
Loosen the screws on the doorknob flange with a Phillips screwdriver or a power drill with a screwdriver attachment. These screws are very long so they can extend through the door to the other side of the lock. They may take some time to unscrew with a manual screwdriver.
Pull the back of the knob off the Dexter doorknob.
Grab the front of the doorknob with your other hand, and pull it out of the front of the door.
Put tape over the exterior doorknob to keep it in place after you have loosened the screws, if you want to protect it from falling on the ground.