bglz42...don't get totally discouraged yet. I've got over 800 hours on mine, and I still have a b***** of a time getting it to shift. I agree with TractorNH on his procedure, and it usually takes me 3-5 tries to get mine to disengage whatever range I'm in.
Also, check to make sure your bolt that goes thru your lever into the linkage is nice and snug. Mine works loose, and it makes shifting that much more difficult. Keep trying to release the tranny pressure. Even if it takes 10 minutes, it's better than ripping the rear end off. The fact that we have HST compounds the problem I believe too...no clutch.
For whatever reason, mine is easier to shift if not in 4WD, and at idle speed.