Siderollo is "snatch"

Good evening.
I'd like to ask you something.
One of my side blinds is quite flabby, the fabric is only taken in laboriously, resp. I have to help out on the last cm.
I tried to spray silicone spray (usually always helps) on the shaft when the Rollo was pulled out. But you can't get to the mechanics, so this doesn't help.
Are there any possibilities here ???? I'm afraid you can't open this thing indestructible.

Greetings Jörg