Load model in 3D Canvas/3DCrafter and Export as a DAE
Bring your textures with you to blender
Open Blender, Import the DAE, attach the textures to the MSTS materials
Use the shading nodes to rename UVS. UVnames need to be renamed to UVMAP for the exporter to work, so every object needs to be renamed... :-( ...which is a bit of drudge work...
Note: I have a SCRIPT to fix this the easy way.
Rework, remodel as needed, update and fix UV's with UV Editor...
RENAME PARTS as needed by the exporter.
Export...
And bam... you have a conversion.
It sounds simple, but it's not. At least not to me.
My progress so far is in the GIF link below... I just need to finish the brake rigging and air-line and do up a WAG file. (and sure, it needs some tweaks here an there as well)
http://i.imgur.com/5uzhy2q.gifv