I do not have access to the user manual for the Thermador MBB microwave oven. But normally one would remove the protective glass / perspex cover and unscrew the faulty bulb from its holder.
Then it is a matter of replacing with the a typical halogen globe available from the local hardware store (have to make sure the stem of the bulb is compatible. Make sure not to touch halogen globes with bare hands to avoid early failure due to contamination. (use cloth gloves or facial tissue).
In case you are unsure give Thermador a call on 1-800-735-4328 in USA or Canada Do post me a comment to say whether this helped
Answers & Comments
I do not have access to the user manual for the Thermador MBB microwave oven. But normally one would remove the protective glass / perspex cover and unscrew the faulty bulb from its holder.
Then it is a matter of replacing with the a typical halogen globe available from the local hardware store (have to make sure the stem of the bulb is compatible. Make sure not to touch halogen globes with bare hands to avoid early failure due to contamination. (use cloth gloves or facial tissue).
In case you are unsure give Thermador a call on 1-800-735-4328 in USA or Canada
Do post me a comment to say whether this helped