How do you repair a polaris sportsman 90 kick starter?

I purchased a used 90 sportsman, which had the kick start arm Welded to the shaft coming out of engine, I just went to replace starter as it was bad and found the broken off piece laying near starter, apparently previous owner just spot welded the actual kick arm to the input shaft that goes to engine. It worked that way for a season until now I am replacing the starter. Pain in the butt! bottom bolt is an Allen that you have to used a special Allen that has the round end because of the angle. Good luck