Upgrading or re-installing over an existing version
For Automated Installs:
All the code files are overwritten completely. If you have customized "ax-admin" or one of the other scripts, then you should save a separate copy of the customized code file and later add your customizations back in.
The data files - log.txt and axs.dat - will remain intact. You can safely upgrade or re-install with no risk to existing log data.
The install process will leave data files intact if a file with the same name already exists. To fully re-install the product, delete data files manually. Then the install process will start you out with default data files.
For Manual Installs:
Replace the "ax.pl" and "ax-admin.pl" scripts. You may need to name these "ax.cgi" and "ax-admin.cgi" on some system.
The files "log.txt", "axs.dat", "red.gif", and "tracker.jpg" can be left as is.
The "free custom install" offer applies to upgrades as well. If you want to have a human perform your upgrade, just contact Fluid Dynamics. Including your web site URL, FTP username, and FTP password.
All standard AXS instances will be upgraded free of charge, with the preservation of existing data. In cases where the AXS source code has been customized, this will not include migration of the custom code. That service can be purchased separately.
"Upgrading or re-installing over an existing version" https://www.xav.com/scripts/axs/help/1036.html