Need Help with Front & Rear Windshield Installation - Duster

The main concern is results. If you hire a professional who warrenties their work and you have a water leak, they get to do it again for free. If you do it yourself you want to be 200% sure it's not going to leak.
If I'm putting a flat glass in the back of a pickup cab I'll use the rope trick. That glass is much less likely to leak anyway.
For these curved glasses front or rear, I apply sealant to the body fence, install the gasket on the fence, apply a bead of sealant in the gaskets glass bed, and install the glass from bottom up.
I dont mind cleaning a lot of excess sealant from the glass and body. Cleaning the all the sealant away to start over in much more difficult.
Did both front and rear of my 67 notch back last summer ( Aug. 2010 ) with reused gaskets.
That rear glass is curved on 2 axis and quite large. 3M Windo-Weld sealant was about 25 bucks per tube and 1 was not enough to do both front and rear glasses
I did replace the vent box to cowl seals and I also replaced the wiper pivot seals.
No leaks today. Good luck with yours