If both front jacks are now working, I would lift the front end with the jacks and then use a jack stand on the frame side that needs to be tweaked. Lower the jacks and let the jack stand do the tweaking. This may allow you to place the stand farther forward then the leveling jacks and have more impact on the frame.
If you get it to tweak back, I would take it for a test drive (even without the windshield, on a back road) to make sure the repair/tweak remains correct.
If you get it back to square, make sure the windshield installer glues the new windshield in. A lot these windshields were just fitted in the rubber gasket and never glued.