<<I did the same for my CC Green GG-1 and My PWC Majestic GG-1. The fast angle wheels loved derailing on the 022 and 072 Lionel Tubular Switches.>>
The later Lionel GG1s didn't come with Fast Angle wheels. Only the earliest MPC ones. I changed mine out soon after I got them.
There's no easy way to remove the wheelsets from GG1 trucks. I place a small flat bladed screwdriver between the outer surface of the wheel and the side frame and pry. It's always worked. I try to flex the opposite side frame out a bit also, it helps. Normally there's enough play and the end of the axle pops out.
