Reset a local user password on Windows Server
Access Local Users and Groups
Click Start > Run.
Enter lusrmgr.msc in the box and click OK or use the Windows® search to search for Local Users and Groups.
In the console, double-click Users to display a list of users on the right.
Reset the user’s password
Click Users in the left-hand pane.
Right-click the appropriate user in the list and click Set Password.
Enter the new password, confirm it, and then select the desired options related to password expiration and change requirements.
Click OK to save the changes. An older version might have Set Password or Reset Password buttons instead of OK.