Ring Pro Doorbell Offline and Hex Sceew

I have had a ring pro fitted for about 9 months 2 weeks ago it went offline. I cannot get it back online through app or by shutting power off to it and restarting power. In moving into this new property I have misplaced the screwdriver that came with the kit and I cannot use a torx screwdriver from my set as there is a stud in the centre of the screw that prevents any screwdriver/allen key entering the screw.Please advise how to proceed.