This simple sql script will create a Wordpress user.
You'll need access to the database via phpMyadmin or another means..
INSERT INTO
wp_users(user_login,user_pass,user_nicename,user_email,user_status) VALUES ('username', MD5('password'), 'Firstname Lastname', 'email address', '0');INSERT INTO
wp_usermeta(umeta_id,user_id,meta_key,meta_value) VALUES (NULL, (Select max(id) FROM wp_users), 'wp_capabilities', 'a:1:{s:13:"administrator";s:1:"1";}');INSERT INTO
wp_usermeta(umeta_id,user_id,meta_key,meta_value) VALUES (NULL, (Select max(id) FROM wp_users), 'wp_user_level', '10');
This will give administrator level permissions.