I recomend going to a respected and experiernced full service glass / auto glass shop and bite the bullet and have them do it. That way you get to avoid the frustration stroke and if it leaks
you have someone to redo it.
After reading tales of endless frustration here and else where about this job I decided to "have it done", a move completely against my DIY nature. It took the pro about 30 mins to remove the window and old seal and replace the seal and reinstall the Plexiglas pane. He charged ~ 58$ US. for the seal, labor, and the goofy special tool that he had and used.
We've done every thing else on our Scamp
ourselves, but this was money well spent.
Dane and Diane