Roof Rack Cross Bar Removal

[nkmoon]

I am trying to remove the off road light bar from my H2. I know that the bars are supposed to slide off the end at the rear. My question is how do I remove the plastic stop at the end? I pull up the plastic tab, but I can't get it to release. I know this has to be something pretty simple but I can't figure it out. Any help would be greatly appreciated. This isn't even mentioned in the manual.

Thanks