Depending on the door lock and style, you may have to remove the knobs to replace the lock. In some cases, there may be a set screw under the knob, and you can remove it with an Allen key.

Popular European smart lock maker Nuki has announced the fifth generation of its smart lock. The Smart Lock Ultra is a third ...

Yale’s Real Living locks feature external posts to which you can connect a 9-volt battery, giving you enough juice to get the door open. Other models retain the traditional key cylinder for backup.