My best results have come from parking the car so the sun heats the rubber for a few hours then cut off the rubber lip flush with the glass and then push it out using 2 people and steady pressure. If it's the original glass or an old replacement the rubber seems to attach itself to the glass so a razor blade after will help too.
Obvious no one was familiar with early Fords as all windshields were framed until 1940 when they were first rubber mounted.
Carefully inspect the windshield frame and find the slotted screw heads that will instantly strip when you try to remove them. If my memory serves correctly the frame breaks apart at the center strip into Left and right halves. There are steel inserts that are held in by the screws. These are "damn" difficult to get apart in the best of times.
You may have to carefully drill the heads of the screws away (they are oval head if I remember correctly) and them slide the frame apart. It would be considerably easier if you wrapped the frame in a blanket and hammered the glass out of it first.
Did I mention that only God the Father, His Son, or the $100 an hour glass man is capable of doing this job? Sorry.
Really, I've wrecked many an early Ford windshield in my day. It's easier to find a good reproduction frame (or even a not-so-good one) or mount the glass flush and blow off the roll-out windshield idea.....