the windshield in my 72 k5 is cracked in several places. I am assuming this has happened because most of the inside of the windshield frame has rusted completely away. I have decided to 'back-fill' the affected area with tiger-hair fiberglass filler. My question is this; do I remove the old windsield first, and fill frame after its out, or does anyone think it would be better to leave it in place until the fiberglass filler is in place? I kind of think it would be better to leave it in, form up the filler around the remaining frame, and then remove windshield afterwards. what does anyone think? thanks for the help!