Hi Weeds, Curt B. is right on the money! The only other advice I would give is not to use engine oil! For a start it's messy! And It won't do the rubber any favors!
I've been installing windshields for 13 years and never heard of using engine oil! A light soap is sufficient! Try and use a piece of cord rather than string.I would agree with the instructions about sealing the screens though. The last thing you need is puddles in your pride and joy!
Good luck and go easy on the glass!!!

1950 Chevy Advance Design 3100 in Scotland
In the Stovebolt Gallery
More pix on Flickr.
I've definately got this truck thing in my blood ... my DNA sequence has torque settings
"Of all the small nations of this earth,perhaps only the ancient Greeks surpass the Scots in their contribution to mankind" Winston Churchill.