Update User Password using PowerShell

In PowerShell type: Set-ADAccountPassword

cmdlet Set-ADAccountPassword at command pipeline position 1
Supply values for the following parameters:
Identity: john
Please enter the current password for ‘CN=john,OU=world,OU=Service Accounts,OU=Users,OU=IT,DC=com,DC=acme,DC=net’
Password:
*****
Please enter the desired password for ‘CN=john,OU=world,OU=Service Accounts,OU=Users,OU=IT,DC=com,DC=acme,DC=net’
Password:
*****
Repeat Password: ****