Uninstalling FFIX , per the OXM instructions , from Square Enix .
1) From your PlayOnline main menu ,select "Uninstall."
2) You will be prompted with the message :
"To uninstall the PlayOnline Viewer/Final Fantasy XI beta version , go to the uninstall menu and select 'Uninstall Software.' Open the uninstall menu now ?"
3) Select Yes
4) Select Uninstall Software from the Install Menu .
5 ) You will be prompted with the message :
"Uninstalling the PlayOnline Viewer beta version and Final Fantasy XI beta version will delete all mails, messages, and all other relevant data . Uninstall now ?"
6) Select Yes .
7) You will be prompted with the message :
"The PlayOnline Viewer beta version and Final Fantasy XI beta version have successfully been uninstalled .
Select 'OK' to exit the PlayOnline Viewer."
8) Select OK , and your PlayOnline and Final Fantasy XI wiil have now been uninstalled from your hard drive .
This info was taken from the letters section of the April issue of Official Xbox Magazine .