Front Door Windows Are Loose

I'm trying to fix up a 1983 CV that my boss just bought (for $150 and it flies), and both front door windows (they're power) are practically flapping in the doors when you put them down. I bought some window guides at AutoZone, but now I can't figure out how to put them on. Has anyone ever installed these things? They kinda fold up and apparently are supposed to snap onto something? I guess I shoulda asked before I left the store, but erroneously thought that they'd be easy to install -- you know, self-explanatory or something. Ha ha.

-Gigi