The drive shaft seals have no trick fixings.
I usually use a very large (MF) flat bladed screwdriver to prise em out
If they are being a royal pain in the ass, try finding a peice of slim flat bar, put a small 90 degree bend in one end & a larger 90 degree bend on the other end.
Hook one end under the seal & smartly tap the other end in an upward motion with a small hammer .... That should get it moving
