The house is late 1940s or early 1950s. Second-floor bathroom.
The compression nut that attaches to the trap has corroded and crumbled away; so the candy-cane-shaped drainpipe, which goes down into a sleeve of some kind in the floor, needs to be replaced.
The drainpipe won't turn in that sleeve using channel-lock pliers. I don't know if this kind of drainpipe was sealed in place with caulk or putty or if it was typically secured in place inside the sleeve using a set screw (if so, the screw could be invisible below a layer of tile, since former owners tiled over tile).
The O.D. of the drain pipe is 32mm, which makes it pretty close to 1-1/4" actual.
How do I remove the drainpipe from the sleeve? Do I use two pipe wrenches, one for the sleeve and one for the drainpipe? Should I torch the connection first to loosen it? Or do I need to chisel out the tile and find a set screw?