Not the easiest job in the world!! even for a plumber.
The bath will probably have to come out to replace the taps as the tap connectors can be very difficult to get off.
This will be to your advantage as you can then fit a proper bath seal to the adjoining walls.(comes in a roll)
It is also a good idea to support the bath with a couple of sturdy peices of timber fitted directly on the flat underneath the bath. The bath support cradles are a complete and utter waste of time, especially if the bath is giong to be used for showering as well.