you need to strip out the rubber and stuff
and there is a lock sheild in the rear runner that's screwed to a bit of the door right at the bottom rear corner so you will have to get the plastic sheet off
there are 6 rivits you need to hold the mechanism in place, these are slightly bigger than normal rivits so make sure you've got some
once the mechanism is ni place and you know it's works you can wind it up and down to suit
make sure the little plastic wheels are off the winder first
then slot the window in at an angle
once the window is in you can then slide the wheels into place and then, using your hands and praying or figuring out how to get a pair of pliers in the gap, squeeze them and snap them into place
then it's just a question of refitting the rubbers, making sure that the rear slider bit slots and clips into place before you put the screw back in again