How do you remove the small plastic triangle that is at the end of the triangular side window without breaking it?

 

With great difficulty. The best way is to get a small flat head screwdriver and lever it up from underneath. It's hard to explain but you want to get the screwdriver under the little **** that presses into the bracket. Otherwise it breaks off really easy. Does that make any sense?

 

Actually that does make sense. I'll try it today. Thanks.