1. Rotate the locking collar 1/4 turn to unlock nose cone from gear case. 2. Pull nose cone off of gear case. 3. To remove: a. Grab the bit holder. b. Push it into the gear case depressing the sleeve. c. Rotate the bit holder until the clutch engages. d. While holding the sleeve depressed, pull the bit holder out. 4. Push and rotate the new bit holder into gearcase, depressing the sleeve, until ball lock snaps in groove in bit holder shank. 5. Replace nose cone by placing on gear case and rotating collar 1/4 turn to align arrow on gear case with the lock symbol on collar.