On the Firebird, it will depend on what rear it has in it. I'm reasonably certain that the Firebird used the same rearends that the Camaro have, the 10 and 12 bolt C clip style, which the EMT trick will work fine with. But I do know that some Pontiacs did use the "Oldsmobile" 10 bolt, which was also used in some Buicks as well. It has bolted in axle with pressed bearings. With those, you'll need a slide hammer to get the axle shafts/bearings out. The EMT trick should work the knock the seals out, though.
