My original was a 40 and the replacement is a 30. I don't know if it is a different part # or the dealer sold me an aftermarket one but in either case it was a Torx.
Go to sears they have some easy out type deals that go over the head of the bolt and has some teeth that grab it and you can back it out. I stripped a bolt that held my starter on and it took it right out I'll post a pic of them
If you have a Dremmel use the cutting blade and cut straight across the top so you can fit a regular head screwdriver and unscrew it. This works for me every time.
Be real careful with the cutting a slot thing, that can actually make matters worse. If it stays stuck even after the Torx suggestions, you might try putting a small bolt inside thhe whole and JB Welding it in there. Then after it dries good you could turn the bolt to extract it.