Fixing broken rear window blind on E66

Hi
The rear window blind on my E66 was broken by the previous owner.
I have managed to locate a replacement, but need advice on how to fit it.

BMW quoted me over £800 to fix it, so I want to try myself.

Does anyone have any information on what is required to replace the blind?

BTW - I am referring to a rear door blind, not the rear blind

Thanks

I think it is very easy to pop it out from holder at least the quarter window on my 2000 was just like that without tools (manual shade) The larger window is from the bottom but it is in a cassette so take off the door panel and it should be visible how to move on.
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