It'll be difficult and take some time to figure it out, but it's doable as long as the character has strong technological and mechanical knowledge! They'll also have to find parts to soup it up and extra fuel...without tampering with the other bikes, since there are only a dozen of them available. But I mean, hey, there's a downed spacecraft in the area. They have opportunities.

Still, these bikes are kinda shitty no matter how much TLC they get, and the fastest they'll go is around 80kmh/50mph. Which will probably be pretty uncomfortable with out a windshield or a helm (BUGS IN YO FACE, as described by one of the other mods because we are incredibly professional).