This is where the tool of your choice comes into play. You will need to provide the .es3 file to the tool. If the file is encrypted, you will also need the encryption password.
It overwrites the old .es3 file on the disk with the newly encrypted byte array. Why Some Editors Fail: Custom Types and Typeshifting
A reliable, working ES3 save editor must include specific features to handle the complexities of modern Unity game saves:
Data is stored using keys (e.g., "playerHealth" ) and values (e.g., 100 ).