As of the latest patch, the most reliable method is using a combined with a manual JSON editor. Here is the workflow for PC (Steam) and Android. (Note: iOS is significantly harder due to sandboxing).
It’s important to understand that using these tools carries inherent risks. Ninja Kiwi has its own anti-cheat system and using third-party programs to edit your game can result in being flagged, shadow-banned, or in severe cases, having your account banned. btd6 save editor updated
Reconnect to the internet and allow the local save to overwrite the cloud save if prompted. Safer Alternatives to Save Editing As of the latest patch, the most reliable
: The tool finds the local profile data (usually stored in the Steam user data folder for PC users). As of the latest patch