The basement is 500 sq feet and is two rooms. Really it's just one big room and a little partition around the water heater and furnace. The furnace will be junked. (There is also 300 sq feet of crawlspace which, of course, has no drywall.)

There are approx 120 feet (length) of walls total. The ceilings are low -- about 6'1". So, the total surface area of drywall on the ceiling and walls combined is about 1200 sq feet. Assuming about 2.5 lbs of drywall per sq foot, it's about 3000 lbs of drywall to tear down and move out to the dumpster. Kind of like moving 60 50-lb boxes, though it will be in all sorts of inconvenient shapes.

I used to do demolition work years ago, when I was a teenager, but it's been so long I'm having a hard time guessing how long this job will take and how much help to get.

So, how many man-hours are we looking at here... assuming motivated and able-bodied persons?

This job is all gutting and no replacement of drywall or studs. I want to get it down to the bare masonry so I can monitor the basement for leaks and condensation.

The basement has a good-sized door to the backyard, with about 5 steps to get up to the backyard, so it will be pretty easy to carry the waste out and throw it in a dumpster.

I figure I'll proceed with the drywall removal by finding studs and cutting off pieces between studs with a utility knife, then prying the remainder off of studs.

Thanks

I think you're probably right that it can be done in a weekend with some help.

Fewer trips with manageable sized pieces beats picking up hundreds of little scraps with a shovel.

A coal or grain shovel is also useful for picking up the inevitable small debris.

Once the drywall is off, a sawzall will make short work of cutting nails holding the studs to free them.
Cutting wood is a lot slower than buzzing through nails.

If you make an initial opening in a stud or just bay large enough to look in the bay you can use a sawzall to cut out panels of drywall for quick removel.