it is virtualy imposible
put the red coded key in the ignition turn it to position 2 quickly 3 times listen for a beep once the beep has sounded leave it in the ignition press one of the buttons on the key in the ignition the the same button on the new key fob that will program the new fob signals to the origanl.
Hold down the lock and unlock buttons, on the key fob, together for several seconds and the system will change to lights with horn.
The dealer scan tool is required.
If you lock your truck with the key fob, you need to unlock your truck with the same device in order to cancel the electronic alarm. If you open your door with the key, the horn will beep louder and faster until you turn on the ignition with the key. Its a security program. If you lock your door with the door lock, the electronic alarm will not be set, and you will not have that beep when you open the door with the key. of course the electronic alarm is not set- so hope nobody tries breaking into your vehicle.
The instructions are in the owners manual. The FOB can be programmed.
PrecisionTune does it here.
A scan tool is required.
The key fob battery on a 2008 Nissan Altima is replaced by using a coin to open the rear of the case. The battery can then be popped out and a new one installed.
check the battery in the car and the batteries for the fob key
Put the key in the ignition and turn the key 2 clicks to the On position and press and release the lock button on the fob. Then press and hold the unlock button on the fob 5 times and then release. This will reset the fob for your Mercedes.
You put the key in the ignition and turn, you don't need a fob in order to start a car.
With the dealers scan tool.