ditto...been there (almost). I twisted a bit, broke a bit on the 1K svc.....but the only thing I did differently was loosen all the screws before I drained it! when I couldn't get it, I tighted them up, drove it to the dealer and told them factory put the screw in too tight, it was stripping. they had a tech come out with a manual impact, removed the screw and put a new one it it. rode home, loosened all of them, then drained! when I did the 1K on my wifes did the same thing just in case..same on my 5K

 

Same here. I had to use a Dremel tool to grind off the head on the bolt. Once the cover came off the bolt shaft unscrewed easily with my fingers. My lesson learned was use the Torx Plus bits, not the regular TORX.

 

I put blue "stick" Loctite on mine. Loctite seals threads as well as keeping them from backing out.

 

I just had the same problem, stripped one out. My local indy shop says he is always removing stripped derby cover torx screws for customers. The local indy sells the chrome allen head bolts with small chrome lock washers. No lock tight needed and they look good.

 

You can try using a small chisel and position it such that when struck by a hammer will force the bolt CCW. I.e., position it at 9 o'clock with the chisel pointing down, then whack it with a hammer. I've stripped a few obstinate Torx bolts (i.e. Derby cover) and removed them this way, but of course the bolts will need to be replaced. To me this method seems a bit less risky than drilling them out. I've since replaced the Derby-cover bolts with chrome Allen bolts from Ace Hardware. So far so good on these.

I don't have an inspection cover on my '07 so I can't go out and look, but this method may be difficult if the cover is recessed too much.

 

Use heat and PB blaster!