Use a plastic putty knife, peel back the rubber on the inside and skirt some soapy water into the seal area with a spray bottle.

Leave a plastic knife or two in one of the corner areas.

Lie on your back inside the van, use your feet to press the window  out with your feet, starting in the corner where the knives are.

If it doesn't come easy, stomp the glass a few times to shake it up.  It will come out without breaking, honest.

It helps if you have a helper on the outside to catch the window although once it starts coming off you can pull it out gently buy yourself...

I've "kicked out" many side windows, many at junkyards with no soapy water.

---------- Original Message ----------------------------------
From:         John Rodgers <inua@CHARTER.NET>
Reply-To:     John Rodgers <inua@CHARTER.NET>
Date:          Sun, 7 Nov 2010 07:01:25 -0600

>  On my '88 GL I have a rust bubble that has appeared under the rubber
>seal on the right rear side window. It's a must that it be repaired
>ASAP. I don't want this thing to grow. It's big enough.
>