This question already has an answer here:
I think I installed the ppa with:
cd / && sudo add-apt-repository ppa:texlive-backports/ppa
Whenever I try to manually update, I get the following message:
Failed to fetch http://ppa.launchpad.net/texlive-backports/ppa/ubuntu/dists/raring/main/binary-i386/Packages 404 Not Found
Please, how do I remove this texlive ppa from my machine without reformatting?