How to remove a stripped screw without causing other damage?

So I finally got an iPhone 6 Plus, I opened it up to check it out.

During the disassembly I found a few QC issues, one stripped screw in particular. It's one of the screw for the battery connector bracket.

Upon close inspection, the screw seems to be tilted, not all the way into the screw boss and the screw head totally messed up. It won't turn at all, and it sits on an area very easily damaged by brute force. I fear I could ruin it further by attempting a removal, but if I plan to go to Apple to replace the battery, this would surely result in a whole device replacement, which is ridiculously expensive. I can't ask Apple to replace the phone now because it's not exactly a good idea to tell the genius that this phone has a stripped screw.

So guys please give some advices on how to remove this screw. I thank you guys in advance on behalf of some irresponsible guy at Foxconn.

Attached is the image of the stripped screw.