Well, if you want to paint the bathtub, it's not that easy. If it's been glazed, it needs to be re-glazed. I don't recommend this job for the DIY. A re-glazing can be done in the house but I recommend you get your wall tiles re-done too. If you remove the tub, you'll end up re-doing the walls too.
Talk to a pro first and see what your options are. My best to ya and hope this helps.