Some advice

[Plumber Tom]

Cut as close to the wall as possible with a sawzall (locate and beware of water and drain lines in the floor) using a metal blade on the sawzall, cut the fasteners holding down the remaining subfloor by running the blade along the top of the joist. This is a tricky cut and may bend up a few blades, but you will be able to pry out the remainder of the floor. Don’t forget gloves and safety glasses.