How to change the admin password

The Problem

You want to change the cq5.6/AEM admin password on the publish and server instance.

The Solution

Go to: (Or whatever the address/port of your admin instance is)
http://localhost:4502/libs/granite/security/content/admin.html

Double click on the admin user, scroll down, click on the pencil icon, and change the admin user. 

NOTE: the first password is the new password, and the second password in the current password. So, for a fresh install, put in the new password first, followed by admin as the second password.

Repeat for
http://localhost:4503/libs/granite/security/content/admin.html or equivalent.