First try to tap in a 6mm bit. Most of the time there is good material a little deaper in the hole. If that fails try tapping in a torx bit[40 I think] Either way always use a bit, and ratchet to avoid this problem in the future
Thanks for the tips but I got it. Apparently I'm what's known as a dumbass. I didn't realize that it was a metric allen wrench that I needed. The plug wasn't stripped, I just didn't have the right tool. I figured that out, but now I have to go back and get another filter because the one I bought doesn't fit. Do you know which one I need? Thanks.