Century Graphic glass back plate stuck?

[SomewhereLost]

Bit of a time crunch so here's hoping.

I took off a film back and slipped on the ground glass back to check focus calibration, but now I can't seem to get this back off without using some force. I'm doing something wrong I'm sure, but what, I don't know. Shoot is in an hour so here's hoping.

 

[Dan Daniel]

The glass back is removed by pressing the two serrated latches top and bottom and sliding it to the right. The sliders top and bottom are to hold the film back on only.

 

[SomewhereLost]

The glass back is removed by pressing the two serrated latches top and bottom and sliding it to the right. The sliders top and bottom are to hold the film back on only.

Million billion thank yous.