$user = "erochester" ; 
$newPass = "[New-Password-Please]"; 

#Change password twice. 
#First can be junk password, second time can be real new password
Set-ADAccountPassword -Identity $user -Reset -NewPassword (ConvertTo-SecureString -AsPlainText "6;wB3yj9cI8X" -Force) -verbose

Set-ADAccountPassword -Identity $user -Reset -NewPassword (ConvertTo-SecureString -AsPlainText "$newPass" -Force) -verbose

#If the machine is not connected to AD, or account is a local one use this instead
net user erochester "[New-Password-Please]"