Login as root to SSH:

service mysqld stop
mkdir /var/lib/mysqlbackup
cp -aR /var/lib/mysql/* /var/lib/mysqlbackup
yum localinstall https://dev.mysql.com/get/mysql57-community-release-el6-9.noarch.rpm
yum install mysql-community-server
service mysqld start
mysql_upgrade -uroot
service mysqld restart
chkconfig --level 345 mysqld on
reboot