You are going to have to drill out the center of the lock cylinder. It will require a succession of carbide drills and a cooling spray. It is a messy job. If you are lucky, you will not destroy the switch housing itself. After drilling, it may come out by itself, or you may need the old slidehammer. This is an excerpt from a war story related to me by a friend who does locks/security. Also stated that MBZ are the toughest ones to destroy. I'm not sure that is of any comfort to you at this point.

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Jeff Lawrence
1989 300e
2000 Dodge Grand Caravan SE
No matter what you fix, there will always be something else to fix..
"Warranty" is just another way of postponing the inevitable.