Mint 15 KDE – one repo is dead

If you’re trying to access System Updates and it gives you errors like

Failed to fetch http:/packages.medibuntu.org/dists/precise/free/binary-i386/ Packages 404 Not Found

Or even if your trying to get a software or tool that you might need in the Software Manager and right after you type the sudo password, the ‘damn thing’ won’t even open…