Mercedes Benz is known for producing high-end luxury automobiles, but just because the factory installed a high-quality stereo in your B-class, doesn't mean that it's got all the features you want. The aftermarket has lots of options available for stereos that fit into the stock location, but first you have to remove the old model. This should take about 30 minutes to do.
Place the hook tool between the air vents above the factory radio and the dashboard, then turn the hook tool so that it's behind the vents. Pull the tool toward you to release the clips that hold the vents in place. Pull the vents out of the dash, and tilt them up toward the windshield. Release the electrical connection on the bottom of the vent connection using your hands, then remove the vents from the dashboard.
Place the hook tool in the gap between the pocket below the heating controls and the centre console and twist the hook tool so it's behind the pocket. Pull the hook tool toward you to release the clips that hold it in place, and then pull the panel off of the dashboard. Reach around the backside of the heating controls and disconnect the electrical wiring using your hands, then pull the bezel around the pocket and the heater controls away from the car.
Unscrew the four Philips-head screws around the perimeter of the stereo using the Philips-head screwdriver. Two of the screws are located in the tight gap between the heater controls and the bottom of the stereo. Lift the stereo out of the dashboard, then disconnect the electrical connections on the back of the deck using your hands. Remove the deck from the vehicle.