Right, so I bet by now you are fed up looking for how to do this! I know we were, so thought we would try and post this and hopefully it will rank high enough for people to find!
All you need to do is, create a Gmail account which will be used for the MCC and then click this link and follow the instructions.
http://www.google.com/intl/en/adwords/myclientcenter/
Hope that helps.