You dont have to pull the oil pump to replace the front main seal. The best way to do it is to put a screw into the seal, and use a pair of sidecuts and put the seal out. And when you put the seal back in use a 3/8 extension to get it seated right(even with the face). The cam seal is about the same with the exception that you have pull the timing belt. ( Reillerated what Running295 said)