Steps to clear out the history of a git/github repository

git-clearHistory

-- Remove the history from 
rm -rf .git

-- recreate the repos from the current content only
git init
git add .
git commit -m "Initial commit"

-- push to the github remote repos ensuring you overwrite history
git remote add origin [email protected]:<YOUR ACCOUNT>/<YOUR REPOS>.git
git push -u --force origin master

Gold

This might be problematic with repositories with git submodules. I believe the recipe in this SO answer is a safer way: https://stackoverflow.com/a/13102849

git checkout --orphan newBranch
git add -A  # Add all files and commit them
git commit
git branch -D master  # Deletes the master branch
git branch -m master  # Rename the current branch to master
git push -f origin master  # Force push master branch to github
git gc --aggressive --prune=all     # remove the old files

Fantastic!
For automation it is better not to use the editor:
git commit -m 'Clear history'

git commit

Will probably need to do git commit -m "some message" instead, to avoid an error.

thanks you so much

Works fine for me. I had a customer who never finished paying me for work, so nuked the code in the remote repo and added my ransom to the README.

...
git push --mirror --force

Thank you, @heshanlk.

Adding a variable to capture the default branch name (it might be master or main):

#!/bin/bash

default_branch=`basename $(git symbolic-ref --short refs/remotes/origin/HEAD)`

git checkout --orphan tmp
git add -A				# Add all files and commit them
git commit
git branch -D $default_branch		# Deletes the default branch
git branch -m $default_branch		# Rename the current branch to default
git push -f origin $default_branch	# Force push default branch to github
git gc --aggressive --prune=all		# remove the old files

Thanks.

❤️

Save yourself a world of pain and use main as default branch... blame Github monopoly for causing this chaos.
In git 2.23 / replit's default / NixOS 22_05 default, use the following, as it has no concept of default branch:

git branch main
git checkout main
git branch -d master

Using just a branch isnt a good concept for branching.

Its always depends about how your workflow looks like and then learn how to branch.

Best regards

worked like charm