1. Do a pull from your #MicrosoftGitHub account for all repositories
2. Add a remote to a freeware respecting hosting service where you've created an account
3. Push to the new service
4. Figure out how to download other data
5. Delete #GitHub account
If you think this is impossible, you aren't trying very hard.
https://infosec.exchange/@0xabad1dea/116308891820413082