Disassemble and remove bathtub–shower combination

I recently took apart the bathroom in my basement. It was a steel tub and I had to bust up the tiles around it to take the screws out, then bust a hole in the other side of the wall to disconnect the plumbing. If you don't need to save it, take your anger out on it. Just be careful not to smash it near the plumbing and be careful to smash it only where it's not directly contacting a stud. If you hit it wrong, you could damage the other side of the wall. I would get everything around it down to bare studs before trying to remove it, just to be safe so you can see what you're doing.

Also, some bath tubs have their base set in thinset. If that's the case, you'll probably need to cut a section of floor board out and replace it.

Depending how badly it was cut, sometimes the only complete solution is a new tub. At minimum, you need to re-cover the wall so that water on the wall runs into the tub - this may require new tiling or a tub surround. Any time a tub is replaced, the walls around the tub need to be done over, or leaks are almost guaranteed. The image is from a ceramic tile site, but the general idea is the same regardless of material - the wall must overlap the tub.