We finally were able to change our Project Sunrise Ultimate 2 back to Project Sunrise Ultimate, unfortunately you need to install the new version from our Technicpack page.
To install the new version you need to have your Technic Launcher open and click on INSTALL THIS MODPACK.
To keep all your data from the old modpack (e.g. Waypoints, Configs, Keybindings) you need to copy everything except for config/mods/scripts from your old folder project-sunrise-ultimate-2 to project-sunrise-ultimate.
You can find all modpacks in your installation directory which is on default at %appdata%/.technic/
If you encounter any problems or need help, feel free to send us a support ticket.