They're standard household fittings, which are all installed the same way. Once you've done one, you'll know how to do it:
https://www.youtube.com/watch?v=6ZmYK41U4kAYou can get replacements from any shop selling plumbing stuff. Lidl occasionally does a sale of various models in their usual reasonably quality for reasonable price manner - that's where all of ours are from and after 5 years they're still fine, although the galley one got some dings and scratches from the big stew pot that barely fits the sink!
The size of the hose fittings can vary but a standard BSP adapter from the same plumbing shop (or the chandlery with a markup) will sort it. Make sure they're well sealed to the work surface or sink, as any water seeping under will corrode them from the inside, where they aren't protected as well.