RBR to rFactor Conversion

[Krizsi]

Hi! I'm new in here. I have a question which is the following: How to convert Richard Burns Rally moldels to rFactor?
I know, the 3D SimEd program, but it can't deal with .sgc file format, so I think first, I have to convert to an another format, but I don't know. I also tried the Z-Modeler, but it's said, the file is locked.
So anyone can help me, please? Which programmes do I have to use? How is the process like?

I would like to convert the Skoda Fabia R5 1.1 (by G. Rodríguez, Garyson, Dino Antonelli) to rFactor.