The only way to get it out of park is to have 2 people- one to pull the gear shift and the other to tap the shifter unit on the right side corner- gentle pressure on the stick and light tapping with the mallet - once out of park you'll be able to drive around but you'll have to leave the key in the car and secure the car with the manual key (bright engineering oversight by MB)
Don't replace with OEM Plastic part - get the non OEM alluminum reproduction
Here is a
YOUTUBE information video you may find helpfull