308GTB roof upholstery removal

[unknown]

Hi from Finland.

New here, first time to write enything that is, and first of all sorry for my bad written english.
I have never had eny issues with my cars(308GTBi, Mondial Cabriolet, Mondia 3.2 Cabriolet and other not to be mention here...) that I can't handle, until now...

GTBi -81, 100% original car, original paint, here whitout it's original wheel and tires.

an upholstery roof has gone bad, foam turned to dust, but i can't get it off.
Has enyone done this job and could give some advise? please...