Broken Bosch oven light lense?

during cooking the light lense shattered dropping glass onto food and the base of the oven. What is left is a jagged ring of glass which I need to remove to fit a replacement. I have ordered the bosch tool for screwing in and removing lenses but I don't think there is enough glass left for that to work. I have tried vinegar etc with no luck. I am now considered smashing the remaining glass with a centre punch and hammer and hope that the threaded section breaks. to do this I would like to remove the roof of the oven. Does anyone know how to remove it?

Heinzy
September 2013