If your dumping the tap and fitting a new one, new tap will come with new set of either flexi hoses (more and more common with taps) or a new set of copper tails, as you have now
To remove tap, can leave copper tails in place at tap end and disconnect them at other end, where they connect to hot/cold supplies
Then bend them forward slightly to access nut on horseshoe fixing as mentioned. This is simple with the monobloc spanners as in link (or similar set)! The tails are annealed copper so soft and easy to bend. Or, once disconnected at supply, can unscrew them from tap, usually just hand tight or use grips / pliers but once you’ve removed the securing nut, can usually withdraw the tap upwards, complete with tails attached (as long as you’ve removed any other fittings such as isolation valves / compression coupler / etc from end of tails