rubber seal goes on the glass first, you could use silicon to glue the gasket to the windscreen and tape to hold it and cure over night, then windscreen to frame, like the above post soap and nylon string( put the string in the seals groove all the way around the gasket with the end on the inside of the car i started at the bottom and worke my way around a dental pick help pull the seal in around the corners, be careful cause the nylon roap can rip the gasket if you pull too hard, just go all the way around and get the lip on the inside of the frame and then use some slight pressure on the glass and pound it home, with the palm of you hands and evenly all the way around and it will pop in the frame just take your time hope that helps,