newbie in need of window fitting advice

[lewis1641]

hi all. my mrs' 5 door 6n was broken into a few days ago and they smashed their way in through the small window in the rear door(ie the one behind the wind down window). i have bought a replacement piece from vw and hope to fit it tomorrow but... i cant really figure out how!

i thought it was a case of pulling out the old seal, slipping that over the new glass then reinserting using the tried and tested piece of string method but i assume this is not the case.

any advice before i start hitting the door with a big hammer would be greatly appreciated!