If you know what you're doing, 30 minutes. I say this because I drove to the factory near me and the owner installed the windshield for me. It didn't take him long.
What I don't know is if the instructions are any good, since he didn't need them. I do remember thinking that there were some subtleties involved that would not be obvious to me had I tried to do it myself. I wish I could offer more specific advice.
If you get stuck, PM me and I will send you photos of my installation (although I will be gone this weekend).