Replacing Vent window

Hi all, I want to remove/replace my right power vent window on my 97 Grand Caravan. I found one at the wreckers that I can get cheap and was in the process of getting ready to remove it.
I was stymied by the seatbelt adjuster track as it's attached with a Torx bolt and I needed to remove it to get to the upper window bolt.

My question is, what size Torx do I need to remove the adjuster track? I tried a metric size but it was too small and the next size up was too big.

By the way, great forum! So far I've been able to easily fix an intermittent gauge problem and a signal issue. Thanks!