well after you unscrew the switch it should just pull out but there has to be a seal there that maybe swollen and causing it to stick
here the the parts diag.
http://pelicanparts.com/914/Parts/Transmission/assembly_small.htm
i dont know for sure but when i changed my switch it did not leak and i would figure that it would with no seal
try calling PP and see if they can check a seal kit to see if there is a seal and maybe beg to see if they can send you one, they should but they might have to order it seperately