If you have followed the fedorafaq instructions for yum you will have repos stored in separate files in /etc/yum.repos.d/
Most of them are disabled by default. You can enable/disable any repo by changing the enabled value in given file.
example:
Code:
su -
gedit /etc/yum.repos.d/livna.repo
Then change the enabled value. 1=enabled, 0=disabled.
or you can enable/disable any repo temporarily for one event
example:
Code:
yum --enablerepo=reponame install application