Go to http://www.volvospeed.com. There would be a link like "Repairs/Maintenance" click there. You'll see a bunch of maintenance headers. there would be some link that says, "... codes" there you would find the exact procedure. As far as I remember, you put the connector to the corresponding socket, turn the ignition to "ON" read all of the codes at least once (this is important you SHOULD read them). then press on the button for at least 5-7 seconds, then the light will blink constantly, then press the button for another 5 seconds. then turn the ignition "OFF" and take the connector out of the socket. Then you can check if the CE light is off. But I should say that I have a volatile memory. It is best to check the volvospeed site I mentioned above.
Ihsan