Saving before all possible endings. If you want to get all the endings, I advise you to start with the "Lord of the Furious Flame" ending, then reload the save and use the needle to remove the curse of the furious flame and get the remaining endings (in fact, after each of them you will have to reload the save again).

Copy the file from the archive to the folder: C:/Users/%UserName%/AppData/Roaming/EldenRing/set of numbers

P.S. Everyone has their own set of numbers!