Thanks for your reply.

Here is our pool information: 24' above ground with vinyl liner.
Hayward Sand Filter (model SL66T92S)
Hayward Power Flow Matrix pump (1 HP)
Performex Sanitizer 940 inline (we use bromine)

Last night, the stench was horrible around the pool. Today, it's not as bad (a little dead fish smelling), but we have disturbed the water at all.

If we were to try to open it, we'd get everything running even though there are white fleshy chunks in there? I guess they'll fill the basket.. We are not positive it wasn't a raccoon, and I read there could be a threat to humans (roundworm I think), but evidently it'd been dead quite awhile.

I'm not sure what your #2 and #3 mean in your response. Does it matter that we use bromine rather than chlorine?

How many days do you think it'd take us to open it without draining/refilling?

If we drain it, we start Monday morning, cleaning the walls and removing debris as we go. That means getting in there with the rotten stuff floating around. The water to refill will begin arriving at noon. I'm nervous about ruining the liner, walls collapsing, etc. Husband doesn't think it will be a problem as long as it's done quickly. He also thinks we'll spend about as much in chemicals ($400) as we would for water.