my battery is dead and i can't get into the car....How do I get into the car. on 2003 Mercedes-Benz C32 AMG

The battery is dead and the key will not unlock the doors. how do I release the hood to put new battery in?

2 answers
The hidden, mechanical (metal) key from "inside" of the smart key fob won't unlock either door??
there is a key that clips inside key fob