AFAIK you can't.
I have never seen tool to see/edit the default attributes stored in the rendering engine.

But if you want to change the attributes of an object (i.e. polygon, polyline or POI) you can add your own attributes to the configuration file of the map i.e. the typ file.
Just use TYPViewer and add to the typ file the object you want to customize ( you must know the type/subtype of the object)