All vassal modules are now hosted on
PG-HQ. The modules which had been hosted by APL have reappeared here as Legacy Vassal Game Extensions.
Vassal for Panzer Grenadier is now run through a central module, which operates with various extensions, according to the game selected. To gain access to the full library, one must complete the Vassal Academy using one if the study paths. (Sorry, but it is a necessary condition.) However, the open part of the library includes the legacy game extensions. To play
Kokoda Campaign, you will need to download the Panzer Grenadier Über Base Module and the Kokoda Campaign legacy game extension. I suggest you also download the Minefields extension, and the PG Über User Guide and PG Über Counter Menu Reference documents.
If you need further help, there are several Vassal players who can answer questions, and when you really want to get into it, give you a serious drubbing.