A bizarre malengineering fault by Bosch which has still not been addressed by them, which is surprising considering the price they demand for their premium products.
You shouldn't need to buy a special tool to remove a simple glass cover over a naturally degradable product like a light bulb.
But thanks to the contributors in here I finally managed it, after several weeks of attempts, using an amalgamation of suggestions in here, so here's what I did.....on a top-mounted Bosch oven light.
I waggled it side to side several times, quite roughly, as I was getting annoyed, then, wearing a rubber glove, door removed, shelves removed, covered the glass with a soft cloth & used a mole wrench to locate against the lugs on the glass & applied extreme violence ANTICLOCKWISE when viewed from below to the thing & it finally agreed to unscrew with minimal resistance, as it was probably fed up with my earlier attempts.
You don't need to replace the large bulb with a fancy Phillips bulb, just a generic oven small screw-fit oven bulb from the supermarket fits fine at a fraction of the price & is just as bright.
Mole-wrench on a cloth against the sloppy lugs on the glass cover, lots of swearing & a final angry lunge & it gives up the ghost & unscrews. Life shouldn't be as complicated as this, Bosch, so address this design fault?
Tony H
June 2016