I am wanting to remove both side rear and rear side roof windows. i have these windows on a parts car and want to keep as spares. Please let me know how i can remove. Thanks

 

From the inside there's a slit in the retaining rubber at the bottom center that you can work a cotter pin removal tool in to, then work it around the perimeter of the glass while pushing on the glass. It will pop out.
Best to have a helper on the outside.