Install and uninstall of MySQL server and client on RHEL / Fedora

Please note that yum is case sensitive and it maintain its own database.

Download MySQL installer and placed into a directory. Unzip that file. For example, you have placed all installer into mysql_installer directory within /u000.
For installation of MySQL-5.6 in RHEL / Fedora server, Prashanth written a very good post.
1. Install shared library first
 sudo rpm -ivh /u000/mysql_installer/MySQL-shared-community-5.x.y-1.rhel5.x86_64.rpm
If you face any compatibility issue, try to install another library:
sudo rpm -ivh /u000/mysql_installer/MySQL-shared-compat-5.1.73-1.rhel5.x86_64.rpm
2. Install mysql server
sudo rpm -ivh /u000/mysql_installer/MySQL-server-community-5.x.y-1.rhel5.x86_64.rpm
Preparing...                ########################################### [100%]
1:MySQL-server-community ########################################### [100%]
You will get message for further instructions required to follow.
MySQL-5.1 has empty password while for MySQL-5.5 and MySQL-5.6 stored default password in a file /root/.mysql_secret

3. Install mysql client
sudo rpm -ivh /u000/mysql_installer/MySQL-client-community-5.1.73-1.rhel5.x86_64.rpm
Only after installing the client, you would be able to use MySQL prompt - mysql>

User management
Login with default credentials ( username root and password mentioned in file for MySQL-5.6, empty for MySQL-5.1)
$ mysql -u root -p****
Now, you will get mysql> prompt

mysql> create user 'newuser'@'hostname' IDENTIFIED BY 'password';
Query OK, 0 rows affected (0.00 sec)

If you want to create user for external access like from application or from any client tool.
mysql> create user 'newuser'@'%' IDENTIFIED BY 'password';
Query OK, 0 rows affected (0.00 sec)

Grant permission (all means - insert, update, delete, select, drop, shutdown, reload, process, file, grant, refrences, indexes, alter etc.)
mysql> GRANT ALL ON *.* TO 'newuser'@'%' WITH GRANT OPTION;
Query OK, 0 rows affected (0.00 sec)
Above command is not secure. You are granting all permissions to this user and that user can make connection from everywhere. So, take precaution when granting permissions.

Now try to access from outside ( from your application or from tool by using hostname, username and password provided in previous mysql command by you).

In the installation information, you will find the location of my.cnf file. There is a single my.cnf file in MySQ-5.6 (/usr/my.cnf) while there are multiple my.cnf files available in different location for MySQL-5.1. To find all location, please run below command
mysql --verbose --help | grep -C3 my.cnf

Below is the command to start / stop the mysql service:

1. Stop MySQL service  - sudo /etc/init.d/mysql stop
2. Start MySQL service - sudo /etc/init.d/mysql start
3. Restart (stop + start) - sudo /etc/init.d/mysql restart 

You can update the parameters values in my.cnf file. After change, don't forget to restart the mysql service.

    Uninstall MySQL completely

Remove mysql server - please note that server version. It should be same as mentioned during installation.

sudo yum remove MySQL-server-5.x.y-1.rhel5.x86_64 MySQL-server

Now, remove the MySQL client:

sudo yum remove MySQL-client-community-5.1.73-1.rhel5.x86_64.rpm

In the same way, uninstall MySQL library:

sudo yum remove MySQL-shared-community-5.1.73-1.rhel5.x86_64.rpm

Clean db cache

sudo yum clean dbcache