Switching back to OS 2

Please don't give me the ol' RTFM bit because I looked everywhere on JJ's sight and through the online manual and I only found where it tells how to switch from the OS2xl to OS1 and vice versa.
Is this not possible once you upgrade to OS 2xl or did I miss something?
Thanks,

os2xl overwrites os2 - you have to flash it each time.