Import-csv into Active Directory
===

I am following [this guide][1] 

I was able to export the Distribution Groups to a CSV, and edit the CSV, but when using

    Import-csv c:\displayname.csv | foreach-object {set-adgroup -identity $_.SamAccountName -displayname $_.displayname}

to import the modifications, I get: 

> Set-ADGroup : Cannot validate argument on parameter 'Identity'. The
> argument is null. Supply a non-null argument and try the command again.

I have tried variations on the theme and no change. Also, I needed to use `-Credential domain\username` when exporting, I have tried adding that and variations of that when trying to import the changes back...no difference. 

1) Wouldn't I need to authenticate?

2) What am I missing as far as importing the CSV? I feel it is simple, like some extra info:  OU, DC, Credential etc.
 

  [1]: http://blogs.technet.com/b/hot/archive/2012/04/26/directory-sync-cannot-update-distribution-group-after-office-365-migration.aspx