gistfile1.sh

mysqld_safe --skip-grant-tables

gistfile2.sql

USE mysql
INSERT INTO user (user, host, password) values('root', 'localhost', PASSWORD('PASS'));

gistfile3.sql

UPDATE user set
    Select_priv='Y',
    Insert_priv='Y',
    Update_priv='Y',
    Delete_priv='Y',
    Create_priv='Y',
    Drop_priv='Y',
    Reload_priv='Y',
    Shutdown_priv='Y',
    Process_priv='Y',
    File_priv='Y',
    Grant_priv='Y',
    References_priv='Y',
    Index_priv='Y',
    Alter_priv='Y',
    Show_db_priv='Y',
    Super_priv='Y',
    Create_tmp_table_priv='Y',
    Lock_tables_priv='Y',
    Execute_priv='Y',
    Repl_slave_priv='Y',
    Repl_client_priv='Y',
    Create_view_priv='Y',
    Show_view_priv='Y',
    Create_routine_priv='Y',
    Alter_routine_priv='Y',
    Create_user_priv='Y'
    where User='root';

FLUSH PRIVILEGES;