Hi Larry,
it is NOT possible to save the installed Packs back from the keyboard to a USB stick.
The only way for you is: You need all original Pack files (.CPF or .PPF). Then delete only ONE Pack at a time in the YEM and import the same Pack newly to the YEM.
If you do it this way, the LSB assignment of the packs should not change. As a precaution, I recommend that you call up the "Change Bank Select LSB" function in YEM first and take a screenshot of this window (or write down the "old" LSB assignments of the Packs).
When you have re-imported all packs where this is necessary to the YEM, mark the desired packs under "Install Target" as usual. Then click on "Save as Pack Install File" to save the .CPI or .PPI Install File on the connected USB stick. Now plug in the USB stick on the keyboard and install the packs there as usual. Alternatively, you can of course also use the "Wi-Fi" method (if the keyboard is connected to your home network via Wi-Fi (stick)).
Hope this helps!
Best regards,
Chris