It should be between the winder handle and plastic disc spacer. Usually when you fit it all back on the disc goes on first and then theclip is fitted to theslot in winder handle then you just push the winder onto the splinedshaft as it has a tapered lead in for the clip to expand then the clip drops into the groove in splined shaft.
But make sure you position the correctly with the window up so its stop position does catch your passengers leg when sitting in the back. othing worse than a winder handle sticking into your knee/leg on a long journey.
I just used a very thin flat screw driver and carefully slighty poped out the top left and then moved to the top right. I caused a little damage to the silver paint covering so I would recommend putting a thin bit of tapeunder the screw driver.
But basically slowly pop the top left out a little and then the top right, then the bottom left and then the bottom right. The clips are tight but the platic seems robust enough.
Push down a little when at the top of the panel to move the clips down to release.
I do have a few more imges I should add to make it a bit more clearer.