First you have to install the cd on your computer. Then click on open file and a list of numbers comes up. You got to go through them all to find the one you need. Just click on a number and click the box that says " notes" and it will explain what the map is for. When you find the one you want, just hook up a serial port cable from the computer to the EMS and click the box " send all " and your map is loaded.i bought it new... but how do i know which map is what on the cd.... it's all just numbers... it doesn't tell you to use this map for this setup???