I had a broken one a few years ago and couldn't figure it out either. I found a replacement window on ebay and just went that route. I tinkered with the old one and still couldn't figure it out.
2013 F-350 CC SB 2WD 6.7PS
2013 Eagle Premier 351 RLTS
-SOLD- 2012 X23B
-SOLD- 2003 Ford Expedition 5.4, Bilstein shocks