If you need to change a User Account Password from your Windows 10 PC, You do not need to use any tools. You can do it easily directly from Windows -> Computer Management without any tool.

First Open Computer Management

Go to Start menu and type “computer” then Right click Computer/This PC and click Manage.

Now You are in Computer Management Window.

Then go to System Tools > Local Users and Groups > Users

Now you will see the list of users including the built in Administrator and Guest accounts. 

Then Right click on the user account (That you need to change the password) and select the Set Password

Now Enter your New Password in both locations.