The undercover has 7 bolts (10mm?) and one plastic locking clip. The oil filter is a cartridge type and requires a cap type filter wrench (76mm X 14 fluit I think). In addition; as wannabe stated, there is an Allen head bolt in the filter cap that is used to empty the filter housing before removal. Don't try to use a pipe wrench or channel locks on the filter housing cap or you will break it.