You can use SLADE to edit myhouse.pk3.
You need to edit the MAPINFO file.
And replace the first part of it with this:
gameinfo
{
//PlayerClasses = "ActionPlayer"
//AddEventHandlers = "ChainsawRemover"
AddEventHandlers = "BillboarderHandler"
}
Essentially, just comment out the lines PlayerClasses = "ActionPlayer" and AddEventHandlers = "ChainsawRemover". This will let you start the two .pk3's together. I am not sure if this breaks anything though. Don't get too excited, it probably WILL break things!
( 3 day old post that was stuck in Limbo. )