An improvement to the most useful answer here:
1] No need to restart the mysql server
2] Security concern for a MySQL server connected to a network
There is no need to restart the MySQL server.
use FLUSH PRIVILEGES;
after the update mysql.user statement for password change.
The FLUSH statement tells the server to reload the grant tables into memory so that it notices the password change.
The --skip-grant-options
enables anyone to connect without a password and with all privileges. Because this is insecure, you might want to
use --skip-grant-tables in conjunction with --skip-networking to prevent remote clients from connecting.
from: reference: resetting-permissions-generic