How to replace a Jacuzzi bathtub faucet
There is no way to replace this from the top.   You have to access it from the side/bottom.  The tub will be glued/screwed in somehow and there will be no way to lift it.  Furthermore, the faucet is most likely soldered into place on rigid copper pipes.  These do not have flexible hoses like a regular bathroom sink faucet.

If there is something wrong with the faucet and it needs repair, feel free to ask another question about that.  Also, you may be able to get a new trim kit for the faucet to make it look newer without replacing the valves.