Key stuck in Ignition
 

Hi All, I have a 2001 ML 320 and my key i stuck in the ignition, does anyone has any idea what is the most common cause for it? I called the dealer they can give me a new ignition for less than $25.00, but I will need to install it. Does anyone has any information and the steps as well what toolsare needed to install the ignition Switch?

Thanks, Neil