Clive thanks for your suggestion.
My garage is about 250ft walking from my house or 200ft in a bee-line from the nearest LAN-jack in my house. BUT, my house is partially earth sheltered (underground; we are off-grid) and my garage is too (we live in the desert in the boonies). There is a huge amount of earth between the two and I doubt that wifi would penetrate. I have wifi in my house and routinely use it with my cellphone. My cellphone cannot "see" the wifi if from the garage. I have a skylight/window that I could remove a screen for a temporary cat5 (just over 220ft Lan_jack to cnc PC). That would probably work as a temporary thing. It would be even more work to remove the PC_portion from the cnc machine and bring it into the house and then it would not have any benefit of being connected to the machine. I could envision possibly having to carry that PC back and forth a number of times. I could also add an outside wifi antenna (from house) and another above the garage then I could flash DD-WRT into some old Cisco routers I have and set them to be a wireless bridge without disturbing the wifi in my house. But that's a lot to do too.
I was just simply trying to do 2 things:
1.) bring it to the attention of forum post responders that there seemed ( to me, a Linux dummy) to be a lack of info about doing various things without any network (e.g. with a USB stick only). It seemed to me that there was usually an assumed network connection.
2.) find out HOW TO do an upgrade (2.5 to 2.6 or 2.6 to 2.7) specifically without a network connection (e.g. with a USB stick).
While there were a number of suggestions, they were all in the vein of 'get it connected to the internet' THEN just follow the directions at the LinuxCNC.org website. I appreciate that those directions are there, but they just don't fit my circumstanced. I feel like a square peg trying to fit a round hole. Being very frustrated, I finally said f@#! it and with some efforts did a full iso install (as it now sits).
While I really do appreciate the good intentions of you and those posters, I was holding out for an answer to my original question about how to do it without a net connection. If anyone posted that and I just missed it then I apologize. I just didn't see any. Clearly I ruffled some feathers, perhaps too much. I'll just back off now.
Thanks anyway.