Ive used the 3 screws method before, straight up into the filter, and outside of the center 1" or so to avoid the mounting boss
just be careful down there.
I recall reading where someguy used the screwdriver through the filter method and cracked the engine case down there.
Smoke em if you got em, and drink your glasses to the bottom...-Will Whitmore
Charter member: T.O. club.