If you wish to update the email address linked to your community account keep in mind you will be updating your Freescale.com email address too, Freescale.com and Freescale Commuity register and login information work as one.
These are the steps that you need to follow:
1.- Log into Freescale.com
2.- Fill the required information
3.- Click the option Change My User Information (name, address, etc.) below the Account Settings header
4.- Click the option Request Email Address Change
5.- Update your email address and click Submit