I've been there. The front motor of my driver's seat stuck in the lowest position, making me feel like I'd slide right off the seat onto the floor. At the same time, my passenger seat switch assembly broke off of the frame
. Fortunately, my extended warranty paid for both repairs at the dealer.
I'll admit that I won't be much help, here, but here's a suggestion...
You might try to slide the trim to the front or side (perhaps lifting slightly at the same time). My son accidentally knocked off a piece of seat trim on the rear of the passenger side and there were little tabs/slots which the pieces connected together. That piece actually looked like you would first lift a little to clear a screw head, then pull. Unfortunately, my son broke the part that goes around the screw head, but luckily, it fit back together with the tabs.
It's also worth talking to a few mechanics or if your dealer's service rep is in a giving mood, talk to him/her. I have had occasions where a mechanic or service rep has been willing to assist with such questions to help me do it myself. Worth a shot...
Good luck.