You upload the file to the web tool. The editor "unpacks" the data, presenting it in a user-friendly interface where you can change numbers or toggle checkboxes.
While some editors are "universal" (designed for specific engines like Unity or RPG Maker), many are built for specific fan-favorite titles: active save editor online
Level Up Your Game: The Ultimate Guide to Online Active Save Editors You upload the file to the web tool
For advanced users who want to manually edit offsets. active save editor online