Pulling windshield and replacing with Percy's, any tips?
 

Is the windshield molding re-used when putting in a Percy's windshield? Any tips or pics of in-progress work?

You can re-use the molding if is still in good shape. Clean out the old adhesive and use some urethane to keep it in place.

I would advise to check the fitment with small spacers installed(to simulate the urethane thickness). We have occasionally had to trim a very minor amount around the pillars and upper corners.

What is good for cleaning out the old glue from the molding? Should I remove all the old adhesive from the factory glass that's still on the car or just use urethane over the old stuff?

If you can get the old stuff out it is best, but if it is to difficult or the moulding maybe compromised then clean it as best as possible with something like acetone real well and apply new urethane over the old stuff. Window urethane is nasty stuff but it works well!

I had to trim the upper corners of mine slightly and put some weight on the top to keep it down until the urethane cured. The corners were long and stopping the speedglass from going far enough up to hold the center of the molding in place. It also was a bit over curved op top and it did not want to sit flat which is the reason for the weights. Definitely check fitment prior to final installation.

I would also advise leaving a thin layer of the original urethane on the car, as new urethane will adhere to that better than bare metal. It is pretty easy to trim it down with a utility knife after the windshield is removed. If there are any spots that are bare metal you are supposed to apply a butyl primer before the urethane.