The 636 has a retasining clip on the oil filter hidepenny make sure you take that off first and i fitted most of my oilfilters so i can get them off easy too but if i get a tough one I just punch a hole through it with a phillips head screwdriver and use that as a handlle, works a treat.
If I rode my bike at the speed of light, what would happen when I switched on its headlights?
bob is right about the philips head trick! cheaper than buying the tool
i found mine came off easy ... just used my hand! just remember u dont have to do them up super duper tight, just screw it on .. then give it a nip sorta thing to secure it ..