Wendersnaven.com (a resource for nwn2 builders)

Another tool for creating hak files is Ranmanu's Encapsulated Resource File Editor.

Edits, imports or exports data from Encapsulated Resource File files also known as ERF files (.HAK, .MOD, .ERF and .NWM).

Can be used for NWN1 (ERF version 1.0) as well as NWN2 (ERF version 1.1).

Get it from the vault:
http://nwvault.ign.com/View.php?view=NWN2Tools.Detail&id=30