Did this last year. You need a good flat head screwdriver and a hammer! Took awhile to get off, I believe there’s a corner that’s best to start at but can’t remember which one. Caution though when screwing back on be careful not to over tighten. Those bolts break fairly easily! I broke one and was lucky that it didn’t leak. I figure if it doesn’t leak I won’t bother with it until next time I remove the pan! Good Luck!
Be careful using anything thicker than a putty knife as you can 'wrinkle' / bend / indent / gouge / UGetTheIdea the lip of the pan and it will leak on reinstall. The bolts / screws should flatten it back down but..
Usually the process involves working your way around the pan a little @ a time.