Help!! Mice chewed alternatoer wires

Looking for advise on replacing my alternator on my 2016 Rancher 4wd manual shift, manual steering. The mice chewed the blue wire in half with only about a 1/16" left and a couple of strands hanging. Unfortunately there is not enough wire left to make a connection.
The big question: How difficult is it too replace yourself I have done them on a motorcycle.
If somebody has done it any tips would be greatly appreciated, I really don’t want to take it to a dealer(bad word).
A bad ending to a good day of hunting.