I've completed the move and the upgrade..just in case other ppl are trying this - this is what I had to do.
0.1) navigate to the xertetoolkits folder
1) rsync user-files to /newhome/user-users (confirm size of the folders in the original location and new (i just used du -sh) and check permissions which on my install are wwwrun:www))
2) rename user-files to user-files-old (the latter can be deleted after confirming all works in the new location)
3) create link to the new home ("symlink ln -s /newhome/user-files user-files"). This means that nothing has to changed in the management UI - I did try changing this - but the code concatinates the location and therefore you get the incorrect path to the new home - hence the need for link instead)
4) ensure that your apache configure has "Options FollowSymLinks" (note: if you are using xerte on https you need to include that option in the ssl.conf file) - restart apache (remember to use graceful if you are on a server with other applications running)
5) move any custom php code to a backup location (in my case this is auth_config.php config.php database.php export.ph)
6) unzip the xerteVx.x.zip
7) run
yourserver.com/upgrade.php
8) take a peak at
yourserver.com/version.txt
9) move the custom php files back
and after that I was "good to go"