Windscreen Fitting

Hi guys took my screen out to treat some rust, got a new seal but am having trouble fitting it. Can anyone share some hints or tips on how to get it back in?  thanks in advance………………..Dylan

A long piece of strong string, didnt you watch camper van crisis?

No I missed it. got the string but im having trouble stretching the rubber over the glass  

its an arse sometimes ,leave it on a hot rad to get it warm for a few hours makes it much easier ,good luck dude          

Or boil a kettle a few times in a bucket and sit the seal in it....use plenty of wd40 or washing up liquid and water to lubricate the seal so it fits easier....