This stuff is old, mainly all 3D editing needs to be done in an editor version release at the time of the games creation in 2006/2007 and same goes for the Collada plugins. It will not work with modern releases.
Extract the tools archive and place the files directly in the “penumbra install directory/redist”, you should have the following .exe in the redist folder
HplHelper.exe
HudObjectEditor.exe
ModelViewer.exe
ParticleEditor.exe
ParticleViewer.exe
SceneViewer.exe
Install .NET
Install COLLADA for your 3D editor
Make sure your editor is set to unit = meter
make sure COLLADA is set to “export polygons as triangles” under export settings