I have a long/thin flat-head screwdriver I just used to pry him GENTLY till he snapped loose at the points he was glued to the throne. It broke the Emperor figure/character itself, but that was fine by me. I only wanted the seat. I got it for 75% off or something too, so it was super cheap.
As you can see in the picture Jayson showed, it's a really great sculpt. Fantastic deco, super detailing on the arm rest panels. It's vastly superior to the POTF2 throne, which was cool in its own right. This one though, has its own base so it sits by itself just fine. Very cool. It's a central focus on my Impy's shelf really.
BTW, I'll second som Imperial artillery... The Vintage Death Star's cannon actually is pretty well-scaled, but requires a base be made for it to sit properly. It's pretty nicely detailed other than the seat being a little sloppy since it's for figures without articulation really. I've seen customs of it that look insanely impressive. I've stocked up on a few of those guns even with the hope of doing a gun section someday. THey're well detailed pieces. I'd love Hasbro to do a new one though, obviously.