I have a leaking counter chainwheel seal. I picked up a new seal and followed the Hayne's workshop manual to make sure I done the replacement right. The book says the remove the sprocket, then the collar and o-ring behind it. The next part is what gets me, it says carefully remove the seal being careful not to scratch the bore holding the seal. When I tried to remove the seal it is pretty much glued in place, the outer ring which the seal fits over is just big enough to fit a utility knife in.... Any tips on how to remove this seal before I lose my mind????