Thanks nite_man, that was the page I was following - but as I say in my first post:
the ./flasher3.0 command does not work (the shell indicates that the command/file doesn't exist). I have definitely updated to 2007 Hackers - the interface changed completely (although the version number on the web site was still 2006, the build number was higher than the standard build number and it specifically said it was 2007 Hackers Edition for the 770)
ssh doesn't work - I didn't install an ssh package, but when I follow the links from that page, it doesn't actually say you need to install ssh, it says you need to install dropbear, and then goes on to say use ssh - which is why I was assuming that ssh was included as part of the dropbear package.... obviously incorrectly! But it does highlight that the instructions are NOT very good. I am a Linux noob - but I'm not an IT moron - I have been working in deep technical roles (mainly server and networking infrastructure) for 20 years, and I couldn't fill in the Linux gaps that I'm not familiar, so a non-technical person has no hope!
So my main questions now are 1) how do I activate RD mode as the flasher command doesn't work, 2) once I have worked out the vi command mode with Zaerc's help pointing me to the instructions, can I just update the gainroot script and then not need to use the flasher command, 3) how do I activate Red Pill mode, 4) is there any chance that I do not have the right version of xterm and that is preventing access to the flasher command (eg, using a different shell, it looks just like a basic Bourne Shell) - I saw that there was a version with build 50 for i386 only, the latest build I found for ARM was 48...??
Sorry about all the questions, just trying to get it all straight in my mind...