You can try something like this (working on a DC within your organization):
$OUs ='OU=one,DC=mydomain,DC=local','OU=two,DC=mydomain,DC=local'
ForEach ($OU in $OUs){
Get-ADUser -filter * -SearchScope $OU -properties Name, PasswordNeverExpires |
Where-Object { $_.passwordNeverExpires -eq "true" } |
Where-Object {$_.enabled -eq "true"} | # don't worry about disabled users
Set-ADUser -PasswordNeverExpires:$false
}
If you want to include disabled users just remove that last Where-Object.
I don't have an AD to test this, so you might have to change the test "{$.enabled -eq 'true'}" to just "{$.enabled}".