To reset your Git repository to a specific commit hash, you can use the command git reset --hard [HASH]. This command will move the HEAD to the specified commit and update the working directory and index to match the state of that commit.

If you accidentally perform a git reset --hard and want to recover the changes, you can use git reflog to find the commit hash before the reset and then reset your branch back to that commit hash with git reset --hard [HASH].

It's important to note that git reset --hard will discard any changes in the working directory that are not committed, so use it with caution.

Always verify the state of your repository after performing a git reset --hard to ensure it matches your expectations.