Password reset for all the users in specific OU

Get-ADUser -Filter * -SearchScope Subtree -SearchBase “OU=ou_name,DC=domain,DC=local” | Set-ADAccountPassword -Reset -NewPassword (ConvertTo-SecureString -AsPlainText “new_pass” -Force)

(Or)

Get-ADUser -Filter * -SearchBase “OU=Service Accounts,DC=Domain,DC=com” | Set-ADAccountPassword -Reset -NewPasword (ConvertTo-SecureString -AsPlainText “Insert Password Here” -Force)