Trustfire probably used thermal epoxy to put that board there. Try a strong citrus degreaser. It'll probably ruin the current LED, but if you don't care about that...
What is the star board glued to? A pill? If you can separate it from the driver, put it on the stove or in a toaster oven and heat it up. The adhesive will soften and release the star board.
Thermal paste and thermal epoxy are different animals. If they used thermal paste, you should be able to dissolve it in alcohol or even heat it up to remove the board. Acetone/strong degreasers are the only things that work on Thermal epoxy, but you'll ruin other things as well. Be sure not to expose the driver to these types of chemicals. You can try heating on epoxy. It's worth a shot. Maybe even freezing it and trying to ship away at it may work.