Assuming that you have acquired a copy of 3dsmax2013.
The first thing you do is go to Raw_Data\
Empire_Design\Campaign_Maps\Sho_Japan.
open up 3dsmax (click on the 3dsmaxscenefile) go to Tools : Manage Layers
as you can see much of the map is under hide status and/or freeze status deselect those buttons
Now you are able to edit trade routes also at sea/nodes being able to select those thus be able to edit those.
First post busy with pictures for this tutorial. ^^