[STLBRZ66]

I referenced videos for 1st gen and yes, much the same. I am starting the process of gutting the interior for soundproofing and speaker/amp upgrades. Pry tool at the front and lift. There are three hooks across the back that hold it down close to the windshield. The door speaker mounts don't match anything aftermarket that I can find. I took a big breath and started harvesting brackets off the OEM speakers to mount aftermarket speakers. I'll see if I have some pics of the limited progress I have made. Love to see your progress.

Attached pics are a Perfect 300 with the tabs cut off so it could fit in the "reclaimed" plastic part of the OEM bracket. Epoxied together. Nothing like cutting up new OEM and aftermarket parts to Frankenstein them.
Second is the woofer from a Perfect 600 set once again in the stock plastic bracket with standoffs epoxied in place to used the tabs.