Symphony Sliding Door internal handle removal

Hi
Does anyone know how the internal strap handle on the sliding door of a 1998 Boxer
Symphony can be removed please? The backstory is that the blind is stuck in the upward position and I’m trying to remove the window surround to get to the cassette housing. I’ve removed the dozen or more visible screws but can’t see a way to take the handle off, without doing which the frame remains stubbornly in place. 
Any thoughts will be gratefully received. 
Thanks
Pat

Solved it! I managed to take some photos of the area behind the handle by removing the trim under the window and could see it was only being held on by two screws concealed under the handle trim. Using a bit of pressure I was able to prise off this trim, undo the screws and  get to the cassette. So just got to work out how to fix the blind mechanism now!