I downloaded the latest installer of the F-104 just today and that to be sure to have the latest Addon Manager...
The F104 installer hasn't been updated yet so, it still comes with an old Addon Manager, and it needs to be updated.
So, as explained already in this section, this is not a problem, you just need to install the Stand-Alone Addon Manager for FS9 AFTER you install any Cloud9 product that do not have an installer made by FSDT yet.
The list of Cloud9 updated installers is posted in this section, on the sticky thread.
How can I remove the Addon Manager from my FS9?
You don't need to remove anything. Just install the Stand-Alone Addon Manager for FS9 (the link for the download it's on every product "Info" page), and it will update it to the current version.