MTFD17, I did exactly that with a mod to an aluminum Dorcy I did for a friend. Everything seemed perfect until we tried to focus it down to get rid of the hole in the middle - the star mounted emitter interfered with the reflector. The star was epoxied over a hole in the heat sink with Arctic Silver epoxy and we broke it loose with no heat. We then needed the emitter seperated to mount on a pedestal...with the star its best to simply flex the PCB but you can't do that with a sink....
For the emitter only, I recommend heat first, I did break one (it was my first attempt) trying to seperate it from a star without heat. Also disconnect (unsolder) any leads first. The razor blade or exacto knife blade works well. Just be careful to get it under the emitter base, not just the plastic before prying. With heat, just inserting the blade usually pops the entire emitter off, you don't need to pry. I think I was using a screwdriver the first time I tried, breaking the plastic (optic) loose from the internal leads.