How to reset the first commit in Git?

When we would like to make a change in the first commit on main, we cannot use interactive rebasing and resetting. Both of them have security mechanisms to prevent this action. Instead, we either have to change our main (using —orphan) or delete the branch while we're on it.

Don't use rm -rf .git. This command deletes everything related to Git in the repository. We will lose all the branches and the commits.

Let's change the main branch.

First, we need to rename the main branch. (We assume a branch named old_main doesn't exist yet)

git branch -m main old_main

-m or --move is used to rename/move the branch and its reflog. This moves everything (all the commits and history) from the main branch to the old_main branch. Now our branch looks like this: old_main:main.

Next, we need to create an orphan branch from the current head.

git checkout --orphan main

--orphan creates a new branch without a root so that the newly created branch doesn't have a history and a parent. The new branch is totally disconnected from all other branches and commits. But it still has all the files from the old_main since we created a new branch while we were in the old_main branch.

The last thing is deleting the old_main since we don't need it anymore. (We can keep it to preserve history if we want to.)

git branch -D old_main

Now we have the latest changes, and we are in a brand new main branch. But there is another way to do this with a single command. We need to make sure we're on the main branch.

git update-ref -d HEAD

This command deletes the branch we are in. If we are in main, this command will delete the main branch, and all the commits.