The piece on the inside of the ignition switch is broken. It should be the same as the other 107's. Take out the instrument cluster and the lower kick panel and you can see the back of the switch from there. You will need to turn the switch to position 2 and insert a tool into the tumbler at the access hole. Then you can turn the ring off of it and the tumbler and the lock can be taken out.
ASE CERTIFIED MASTER AUTO TECHNICIAN
SERVICE MANAGER FOR 14 BAY FACILITY
MERCEDES SPECIALIST 8 YRS
PARTNER IN MERCEDESSHOP.COM