[ambari] how to reset ambari admin password

#psql -U ambari ambari

 Enter password 'bigdata'

In psql:

update ambari.users set user_password='538916f8943ec225d97a9a86a2c6ec0818c1cd400e09e03b660fdaaec4af29ddbb6f2b1033b81b00' where user_name='admin'

 Quit psql

 Run 'ambari-server restart'

This will reset the admin account back to the password of 'admin'

How to reset Ambari Admin password? - Hortonworks 

https://community.hortonworks.com/questions/449/how-to-reset-ambari-admin-password.html