Zafira 2005 pond cover, it does not open

Hello everyone, I tell you that I have a 2005 Chevrolet Zafira and I have problems with the fuel cover sheet, when I act on the doors opening control, they open all except the benchin pond lid, I imagine that it must carry an electric motor and it must have failed, the problem is how I can take fuel. Where can I get to that engine?

Greetings

I have a vectra and to avoid this problem, Opel mounted a ring and a shooter that are manually activated from inside the trunk, on the side on which the filling cap is.

This ring is behind the upholstery, in the hole for the kit, the triangles, the cat, etc.

All the best.