There is no universal "one-click" editor for PC. Advanced users often use a Hex Editor (like HxD) to manually adjust values. The save data typically begins at hex block 13 . If you are transferring saves between different versions (e.g., from a retail version to a different launcher), you must often copy the data starting from this block into a new file with the correct header.
C:\Program Files (x86)\Ubisoft\Ubisoft Game Launcher\savegames\ \856 (or folder Technical Context & Issues
The most streamlined tool for managing and backup editing PC saves is the . This is baked directly into the custom mod installers used by the community.