What are you stuck on?

I've done a hatch and would assume the estate is the same;

Doorcard and weather seal off obviously.

Wind window down about 1/3 of the way until you can see the white plastic peg through the hole in the regulator strut (an oblong hole)

Push the centre of the peg out then push out the outer bit (the outer bit is about the sze of a polo mint.

Lower the regulator all the way and wriggle the glass out of the holder.

Pull the rubber liners / guides out of the window frame

Wiggle the glass out of the frame.

Refit is a reverse Ha hah ha hah hah