Install the repos with the following commands:
wget http://dl.fedoraproject.org/pub/epel/6/x86_64/epel-release-6-8.noarch.rpm wget http://rpms.famillecollet.com/enterprise/remi-release-6.rpm sudo rpm -Uvh remi-release-6*.rpm epel-release-6*.rpm
Now, enable the Remi repo to be always enabled by editing:
sudo vim /etc/yum.repos.d/remi.repo
…on the topmost repo (right under the [remi] tag).