SLC CERN 6.x Repositories in the Scientific Linux 6.x

1. Download sl-release file:

i386: http://linuxsoft.cern.ch/cern/slc6X/i386/yum/updates/repoview/sl-release.html
  Or,
x86_64: http://linuxsoft.cern.ch/cern/slc6X/x86_64/yum/updates/repoview/sl-release.html

2. Open package with file roller, and extract files.

3. Open folder, and go to the this package's location: [package] /etc/yum.repos.d/

And you'll see these, and other repositories files:

slc6-extras.repo
slc6-os.repo
slc6-testing.repo
slc6-updates.repo

4. Copy these files to your system, open terminal as root in the [package] /etc/yum.repos.d/ location, and copy files:

root# cp slc6-extras.repo slc6-os.repo slc6-testing.repo slc6-updates.repo /etc/yum.repos.d/

5. After these steps, we can try to use slc6x repositories.

root#: yum check-update