Ours wasn't a real fireplace, it was a massive surround with a gas fire in, made from odd shaped flat stones, real ones, not cement fakes. It had a plinth one side to stand a TV on and a little shelf on the other. We bit the bullet and removed it (well not us, a nice man) it came apart quite easily but messily, loads of dust.
We put in a new smaller real flame gas fire with hearth and surround. The wall needed replastering and we recarpeted to fill in the space between the old huge hearth and the new much smaller one. It wasn't cheap but very pleased with the result. Its now 15 years old and still pleased with it.