Harness provides tools and methods to securely remove sensitive data from Git repositories, enhancing data security and compliance. Sensitive data, such as encryption keys and API tokens, can be compromised if pushed to a remote repository. To address this, tools like git-filter-repo and BFG Repo-Cleaner are recommended for purging sensitive information from a repository's commit history. The git-filter-repo tool, a flexible and open-source option requiring Python, can remove sensitive data from the entire repository history. BFG Repo-Cleaner, a simpler and faster alternative using Java, also effectively cleans sensitive data. Both methods require creating a backup, cleaning up sensitive data, and updating remote repositories. It is best practice to add sensitive file paths to a .gitignore file to prevent their addition to the Git index, and any sensitive files can be removed from the index using git commands.