The Bernina Bulb Remover Screwdriver is a very handy chap. Use him to loosen, or tighten, the needle clamp screw on older Berninas. The type with the small knurled thumbscrew that holds the needle.
The other end of the screwdriver is a bulb remover. You will note by the size that it only works on the small bayonet bulbs. Not the larger type. There is in fact another Bulb Remover available for the larger bulbs.