I change the pump in my '91 wagon a few months ago. After 180,000 miles, the strap bolts were hit and it was late. I cut a hole in the floor right underneath the bastard seat, changed the pump. Used what they call 'panel bond' to re-seal the hole. Some urethane primer and I was done. Less than two hours and I wa back on the road. This included splicing in a quick disconnect for the pump in case it happens again. (hope not!)
I don't blame you. I'm not sure why you need a quick disconnect though - there's a stock one there already on my car.
It always happens when you have a full tank of gas, and the internal baffles make it almost impossible to siphon out the gas. If you could, where would you put 20 gallons of gas - buy 10 gas cans or use Gatorade bottles? What an insanely stupid design - why didn't they stick with a remote pump like they used before?
When my '92 Caprice fuel pump broke no way I was going to take it out the "right" way so I cut a big hole and did it like you did. Ultimately I would find a second vehicle and cut out a larger panel to make a cover - something that overhangs and inch all around. I used (not my proudest work) foil tape to put back the cutout, which was only a big "U' shape. But under the carpet , fold down seat and fold down floor no one will know and it was a zillion times faster than doing it the stock way. And if the pump failed this week I'd sure be glad I did it. No regrets on this one.
My feeling was, just because GM blew it by not making an access panel like many other cars have doesn't mean I have to go along with it.
It cut easily with a Dremel fiberglass reinforced cutoff wheel.