That's about the only thing that isn't reversible. At least a nut is easily replaceable for a qualified luthier. At least you can lube it yourself.Yes, no question about whether buyer can set it up by himself. There are so many tutorials etc. Truss rod tighten, bridge down and so on BUT if the nut is not correctly cut you are pretty much stuck, starting with the nut cutting etc. is not really welcomed as DIY.