Hi Colette, you have to remove the radio by pushing the removal tool into the 4 small holes in the front of the radio, if you dont have the correct tool (halfords £5) you can use an old wire coathanger cut both ends off and this will work the serial number will be like M123456 it should be on a sticker and engraved into one side when you find it re-post your request with the serial nunber
nigel, April 2008