Cam plug leaking. Removal and replacement?

Spank him! Now because it's in backwards that will make it easier to remove. The lip edge of the cup is somewhat rounded. Take a LARGE flat blade screwdriver or a pry bar and give it a swat (the pry bar) at a almost vertical angle, to try and create a good "kink" in that exposed lip of the cup and at the same time try and leaver it out with the pry bar.