My VN900C has decided that when I push down on the shift lever, it won't return back to the center position. Lifting up on the lever does return to center. I'm guessing it's the return spring (assuming there are 2 return springs, one for pulling the lever up, and one for pulling it back down), but I was wondering how hard that spring is to replace? Is it something I want a mechanic to do? Or is it easy enough for an amateur to do?