The truck doesnt move from parking

Stick an Allen wrench in the little black trap door at the base of the gear shifter console inside the cabin While gently but firmly moving the gear shifter toward reverse until it releases. MB recommended "sticking a pen or pencil " in that hole but I used an Allen wrench because if the pencil or pen break off there will be bigger problems. If it does not release then leave the wrench in the hole and try turning the wheel while simultaneously trying to release the gear shiter. It should work right away. Take Allen wrench out of gear shifter console hole and keep in ashtray or glove compartment for emergency. DO NOT FORCE THE SHIFTER. If not successful have vehicle towed to your mechanic! This happened to me a few years ago 7-10 times on both my E320 4Matic & ML320 (model years- 1998-2003).It has not happened since. This is a Lifesaver & Free! I Hope this helps! Donna