Very good question, but to get the best solution .. it would be most helpful if you shared a photo. There can be numerous variables based on the site and product conditions.
Yes...pics would be helpful. A traditional tub is set on the floor or along some wood "cleats' that are attached to the wall studs...then typically the backer for the tile is set above. When acrylic tub enclosures are used the "sides" are normally set in a similar fashion. I most cases the sides and a course of two of tile need to come away first to allow the tub to come out.
I need to post the pictures.
Sometimes a tub is set into a cement filler to keep it secure if it's not cast iron, that's how it was with our old one.