One can use a SSH console to place files onto the USB stick, but if it's many files, doing it this way is painfully slow. So I installed a 4PDT switch and a USB jack to allow the USB stick be available to a computer. So I can drag and drop files in Windows into the USB stick like any other USB stick. I have this switch switch the USB lines (D+, D-, 5V) and in "external computer access to the USB stick mode" powers down the router circuits. This avoids the router from reconfiguring itself to be without the USB stick. The switch doesn't appear to mess up the signal line quality.

http://www.wa2ise.com/radios/usbstickswrouter.jpg
I used some Kapton tape to mask off the adjacent resistors before I changed resistors RH19 and 20, to avoid accidental removals. 

http://www.wa2ise.com/radios/routerwithusbinsw.jpg

http://www.wa2ise.com/radios/routerwithusbback.jpg

(Last edited by wa2ise on 27 Jul 2017, 21:38)