First of all Congratulations on your new M7 - I have the same combo you have plus a Skyline S9. My sewing room still has room for a few more, but I think I’ll stop so that I can move and have 2 or 3 friends come to have a sew-in with me.
The update is not difficult - basically the same as all the other updates have been in the past on Janome machines - you do need a clean Usb though, that doesn’t have ANY files on it - so I formatted mine in the computer - NOT the sewing machine. Download all the directions and there are about 3 different ones to look at and read them all - boring reading, but I found that it did help. Where my difficulty came was after I’d downloaded and transferred everything that was required to the USB was HOW did I do the update on the sewing machine - I had somehow missed the page in the instructions that told us which buttons to hold down on the sewing machine as we turned it on to blank the screen so that things could happen - DUH! I called my dealer for help, to find out that the lady she assigned to update the store’s machine wasn’t there as she didn’t know “how”, “Could I wait until tomorrow, when she’d be back to work?” Of course, I said “Yes”, and then went back to all my instructions and found that the 2 buttons that needed pushing were the “Lock stitch and Up/Down”. So within minutes I had the process working - I went and had my supper and when I was done, everything was “finished” and my screen was blue as it should be.
You’ve obviously downloaded and un-zipped the files, so I suggest that you format your USB or use a different one, and do the transfer to the USB and try again. That machine is way to heavy and big to need to take in for the dealer to do what you are capable of doing yourself.
Let us know know you make out.
Cheryl - Saskatoon