You don't need to change your password for 'Great People' at work. You can change it from home. Click the forgot password and answer your security questions, then you can change it. You only need to change the websites you have to be at work to access, at your work.
The password for Great People, ess.kroger.com and the RF handheld is all the same, and yes you do have to change it at work. You have to log into passport to change it.