i just got a new 6" from elemental designs and i am planning on just taking out the old subwoofer casing, cutting the hole bigger and making it flush, then placing the new sub in it (since it doesnt fit off the bat). I unscrewed the bottem screws on the left and right but there seems to be somethign else stopping it from ripping out. any ideas?

There should be more than just 2 screws holding the sub in. Did you check the top of it too?