Wheel "helper" piece stuck

[sokoloff]

I swear I am getting incompetent in my old age or maybe I should say more incompetent. I'm in the middle of doing a B service on my E300D which I have done probably fifteen times before with no issues. I can't believe the problems I'm having this time. I can't start the car after changing the fuel filters. I had lots of problems resetting the maintenance due indicator. My pressure bleeder for bleeding the brakes isn't working and now this one.

I was removing all the tires to check tread depth, brake pads and rotors. All went well until I hit the last tire. I generally hate to bother with that helper pin that screws in to help guide the tire into place. But in this last tire I just couldn't get the tire lined up right, so I used it and the darn thing will not now unscrew. I only screwed it in hand tight, but not even pliers will get it to come out. What are some simple options I've got?

Thanks.