Okay, took me forever but I figured it out, sort of. I took a flathead, slid it under the switch, there’s a small tab that hooks on to it. I just used a little bit of force, and it popped right off. No clue how, but with a flathead or pry tool, just slide it under and it’ll come off. Then, there are two tabs holding the thumb piece to the switch. Use magic and pop the thumb piece out and off. Then you can finally remove the screw hidden under the switch.
After the screw has been removed, I actually found this part more difficult than I anticipated. The front piece has grooves on the edge of the leather and where the plastic meets. I again used magic and some force with a pry tool to pop it out of its groove, and finally removed the front piece. Then reverse all your steps and voila, got a wonderful alcantara shift knob for the GT2.
Good luck!