Presuming you are using Redhat or CentOS and yam command is available .

1.  yum install mysql-server

2. /etc/init.d/mysqld start

3. mysqladmin -u root password ‘{password}’, if it gives issue try to reset default password in this manner

4. /etc/init.d/mysqld stop
   mysqld_safe –skip-grant-tables &
   mysql -u root
   mysql> use mysql;
   mysql> update user set password=PASSWORD(“newrootpassword”) where User=’root’;
   mysql> flush privileges;
   mysql> quit
   /etc/init.d/mysqld stop
   /etc/init.d/mysqld start