Install Uninstall MySQL Packages

First uninstall all the MySQL packages installed on your server

 # yum remove mysql mysql-server

Now we need to remove MySQL data directory from system which by default exists at/var/lib/mysql. If you didn’t find this, It may be changed to some other place, which you can find in my.cnf file with variable datadir. Delete the /var/lib/mysql directory from system but we prefer to rename it to keep a backup of existing files.

 # mv /var/lib/mysql /var/lib/mysql_old_backup

After removing MySQL completely, install it again using yum package manager, It will re create mysql directory under /var/lib/.

# yum install mysql mysql-server

After completing above three steps, now you have a fresh MySQL install on your system with new settings.