Fitting the door handle. Drill two holes through where you made the marks. Remove wood shavings. Next, fit the door lock in the hole and screw it into place. Finally, place the thumb turn handle through the holes and secure them with screws.Click to see full answer. Thereof, what size bathroom lock do I need?Bathroom door locks are generally required for privacy rather than high security. Standard case sizes for full bathroom locks are 63/64mm and 75/76mm. The 63/64mm size tends to more widely used, however sometimes the design of your door may require a different size.Also Know, how do I take my bathroom door lock off? Removing a Mortise Lock Step 1: Locate & Unscrew the Set Screw. This screw will be on the shank of the inside knob (the one you use to lock the door). Step 2: Unscrew the Door Handles. Step 4: Remove the Rose Plates. Step 5: Remove the Face Plate. Step 6: Remove the Mortise Lock. Step 7: Filling this Hole. In this regard, how do I remove a bathroom lock? Undo all the screws that fix the handles to the door. on the thumb turn on the inside handle of the bathroom there should be a tiny allen key grub screw. Usually at the bottom of the thumb turn. undo the allen key grub screw and take away the thumb turn and spindle.What is a Thumbturn?A thumb turn (or turnkey) is an oval or crescent shaped knob used to operate the dead bolt of a privacy or entry mortise lock. Our thumbturns are available in sturdy brass and iron and include thumb turn, back plate and spindle.