To run this, you can try:
curl -ks https://gist.githubusercontent.com/nicerobot/2697848/raw/uninstall-node.sh | bash
I haven't tested this script doing it this way but i run a lot of my Gists like this so maybe this one'll work too.
Alternatively,
curl -ksO https://gist.githubusercontent.com/nicerobot/2697848/raw/uninstall-node.sh
chmod +x ./uninstall-node.sh