I've just mastered this after years of struggling so thought I would share!

I'm talking about the standard Holden cargo barrier with the two hooks at the bottom.

1. lie the back seats down

2. unlock the top barrier fittings (the easy part)

3. let the barrier lie back as far as it will go

4. from inside the car (ie over the back seat), lift the hooks out of the floor one at a time - a little jiggle may be necessary but when in the right position they lift straight up - basically there's a big hook facing the rear with a little spur facing front - the barrier will come to rest on the wheel arches.

Hope this helps someone!

Peter