Ten years ago I registered my GitHub account as alexr007. It felt fine at the time. GitHub eventually made it possible to rename accounts, and the moment I found out, I switched to djnzx.

The rename on GitHub’s side is instant — all existing repositories redirect automatically. The problem is every repository already cloned locally still points to the old remote URL. Updating them one by one is tedious.

A single command handles it with sed:

git remote set-url origin $(git remote get-url origin | sed 's/alexr007/djnzx/g')

This reads the current remote URL, replaces the old username with the new one, and sets it back. Run it from within each repository that needs updating.