Modding save files is a grey area. 2K/Visual Concepts have not officially banned players for save editing in Battlegrounds because there’s no competitive ranked mode. However:
Never overwrite without a backup.
As of this writing, the most reliable sources are: wwe 2k battlegrounds all characters unlocked save file hot
On consoles (PlayStation, Xbox, Switch), save files are encrypted and tied to specific user profiles, making shared saves nearly impossible without third-party modding tools. On PC, however, replacing save files in the local game directory is technically possible. Modding save files is a grey area
For those who may be new to WWE 2K Battlegrounds, here's a quick overview of the game: wwe 2k battlegrounds all characters unlocked save file hot