Copy/paste from our "Internal" forums, note that I've not tested these settings personally but another SE verified them as working:
*************************************************************************
To specify their .lar file as the default home page you need to go to the file:
C:\Program Files\Nimsoft\probes\service\wasp\webapps\ROOT\WEB-INF\classes\portal-ext.properties
In that file you'll need to change the following property:
default.user.private.layouts.lar=<path to the file>.lar
It would be best if their .lar file was kept in the directory specified above.
Then restart the wasp.
-------------------------------------------------------------------------------------------------
Note: I also dicovered that when you Export a new LAR file for this purpose, it seems to work best with the following options ticked.
Pages
Portlets
Setup
Archived Setups
User Preferences
Data
Range: All
*************************************************************************
Dustin