How do I remove my once piece ceramic shower unit?

I recently purchased a condo where the 2 bathrooms haven't been updated since the 80's. The main problem are the ugly frog green full tub/shower combo and the 1 piece shower unit; also green. They're completely ceramic and therefore heavy. I'd like to remove them and install new updated units. How can I do that? Can I take a sledge hammer to them and take them out in pieces? I've looked into resurfacing but want alternatives. Please don't comment with useless info.