in the uix.ini file located in the system folder in the UIX dir you will find the following lines
This is the name of the directory you would add in your E, or F drive. Then from there you could stick other dashboards like Avalunch, MXM, Evox, and etc in the Dashboards directory. You can change the name and path in the uix.ini to what ever you want but it needs to coinside with the directory you create on the E/F drive of the xbox.
Hope that helps
Of course once you hit back the dashboard menu make sure to press the y button to refresh any changes you have made.