I've just replaced the windscreen on my Defender while doing a bit of a respray and tidy up. I bought a shatterproof (Not Shatterprufe) for R500 and decided to do it myself as I've done it before, except last time I cracked it. I also put 35% smash and grab on all the glass. R600 odd for 3m x 1.5m. Bit of a learning curve a few small bubbles but I'm happy as the bubble are where there are pits in the glass. (and I saved myself R1000)

I followed this advice

Had it done in 20 min flat.

Tips to follow :
1 - Use plenty of lubricant. Best is 50:50 green washing up liquid and H20
2 - Pour lube down groove on the inside of the rubber and fit the rubber to the windscreen.
3 - Put your cord in the outer groove and pour the lube in the groove.
4 - Have someone !gently! hold the windscreen square with the frame.
5 - Pull the cord from both sides evenly. Make sure that you don't get one side in first otherwise you will struggle.
6 - DONT!! try to push the screen in from the outside especially the corners as this WILL crack the glass!

Thats it! and Remember PLENTY of LUBE.