my ground stud busted off my starter

Only way to fix this is to change the starter solenoid and Here's what it looks like http://www.napaonline.com/Search/MultiImagePopup.aspx?ImageIndex=0&A=SOLSD504_0059478250&An=599001+599999+101993+109999+50014+59999+2014048+3999999+14365 about $15 to $20 at the parts store

Use a torque wrench next time, and look up the torque spec in the shop manual.