Removing power tap g3 battery cover, without tool

Are there any suggestions for a makeshift tool to use to remove the battery cap / cover on a power tap G3 hub? I’ve lost mine and need to swap out batteries before I will have a chance to get to a store.

Jar opener or strap wrench.

Are there any suggestions for a makeshift tool to use to remove the battery cap / cover on a power tap G3 hub? I’ve lost mine and need to swap out batteries before I will have a chance to get to a store.

All I can say is I did it. In Los Cabos for that matter with access to hardly anything so I know it can be done but don’t really remember how. I think I scratched the cover to create a deep groove to gain leverage with a tool. May have used a wide pliers at that point or maybe a couple of tire levers.

I used a rag & a vice grip.

I used a old mountainbike innertube and a large socket.