# stop the mysql service
> systemctl stop mysql
# launch the service without grant-tables and networking (to the background)
> /usr/sbin/mysqld --skip-grant-tables --skip-networking &
# login to mysql as root
> mysql -u root
# flush privileges
mysql> FLUSH PRIVILEGES;
# set the root password
mysql> SET PASSWORD FOR root@'localhost' = PASSWORD('itbible');
# exit back to bash
mysql> quit
# kill the running session that you launched to the background
> kill %1
# start normally again
> systemctl start mysql