Window/channel guide help

I have a 1985 Chevy S10, and the passenger side window has fallen off of
its track. How do I put this back together?

I am able to get the window back on the track that allows it to roll up
and down, but whenever I roll it down, the window falls out agian
because there is nothing holding it from the sides.

I have the HELP brand channel guides, but have alot of trouble getting
them on and I probably need new weather stripping because there is a
piece ripped out from were the channel guide came out the first time.

To sum this up, I need help/ideas on getting the channel guides on, and
the name of a place where I can buy new weatherstripping because the
Checker near me doesn't seem to carry it.

Thanks

-Mike
Tucson, AZ