wtf are you guys talking about ^^
Muscle? Yes, let's muscle in the stripped bolts that hold the seat to the floor. Good idea. I'll leave the "weld it" comment alone.
Inserts would work, but it's more of a pain in the ass than he needs.
Just get a tap, as in tap and die. The exact same thing happened to me and I just ran a tap through the hole. Needed very little pressure to get through and it worked perfectly. Don't try to reuse the old stripped bolts though. Go to Home Depot and replace them.
Harbor Frieght Tap and Die set - 40 pc metric $12.99 (cheap for this set) -
Harbor Freight Tools - Quality Tools at the Lowest Prices
Make sure that set has the size you need. I don't remember it off the top of my head.