How do I manually update/change an end-users password?

Here you will learn how to change a user's password via the admin section

Step-by-step guide

1. Log in to your administration panel admin.yourwebsiteaddress.com
2. Click "Contacts" on the left-hand navigation
3. Click "Browse All"
4. Search for and open the user's profile
5. Select the Gear icon next to the customer's name. 
6. Scroll down to where it says "Password." Enter the new password here..
7. Click "Save" and the password will be updated.