This document explains how to change your local account password in Windows 8.
Move your cursor to the upper right corner of your computer screen to reveal the Charms Menu.
In the Charms Menu, left-click or tap the Settings icon.
Note: You can also go directly to the Settings menu from any screen by using the key combination Windows + I.
At the bottom of the Settings menu, left-click or tap Change PC settings to open your PC settings options in the Windows 8 User Interface.
Select the Users tab on the right. Under the Sign-in options section, click on the Change your password button.
A new window overlaying the Users screen should appear. Type your current Windows account password in the Current password field, then click Next.
Type your new Windows account password in the first two fields, add a hint, then click Next.
If the password reset was successful, the next screen should read, "Next time you sign in, use your new password." Click Finish.