To install a key lock on a sliding glass door, drill two mounting holes, fasten the lock onto the door with screws, and drill the lock bolt hole. Test the lock with a key.
- Clean the track, and drill the first mounting hole
Clear dirt and dust from the door track, align the lock at the base of the door, tap the base of the outer glass to locate the point where the glass ends, and use a sharpie to mark the point. Hold the lock straight against the inner glass, align the bolt in the lock with the mark, and draw a circle in the lock's top screw hole. Hold a steel punch in the center of the hole, tap the punch with a hammer to create a slight indentation, and slowly drill a fairly deep first mounting hole into the glass.
- Mark and drill the second mounting hole
Align the lock to the inner door frame, insert a screw into the drilled hole, and fasten the lock onto the door. Mark the other screw hole with a sharpie, drill another hole, and screw in the screw.
- Drill the lock bolt hole
Push in the lock bolt, mark around the bolt, unscrew the lock, tap an indentation, and drill the lock bolt hole using a 1/8-inch drill bit followed by 1/2-inch bit. Screw the lock, slide the bolt into the bolt hole and test the lock with a key.