You may need a strap wrench to get it off. If it is really tight, use a hair dryer on just the back piece to help expand it a bit.
Careful once you have it off. The protruding threads it attaches to can get pushed into the back end of the SCT. No big deal but it can be disconcerting to walk away and come back to see them missing.
A friend of mine momentarily thought he had broken off the threads of his 14".
A benefit of the AP reducer is that the adapter opens up the visual back to a full 2". Helpful with wide angle EP's
Pesse (Why Meade, in its infinite wisdom, designed this 2" back and then stepped it down to 1.25" is beyond me.) Mist