Trick for removing pedal:
Put the crank arm at 6:00. Now put your wrench on the pedal flats, at the 10:30 position. Squeeze the two together. (You'll be trying to turn the pedal axle clockwise to loosen it.) Squeezing with both hands is a lot easier than one hand on the wrench and the other on the crank arm. And you won't gouge your knuckles when it finally loosens. I think pedals for an ashtabula crank take a 9/16" wrench?