Sky & Skyboxi problem

I am trying to convert Baltimore from rfactor to GTR2 for private use (for now)
I get CTD and the sky & skyboxi will not show up in 3Dsim. ( I think that's the problem.)
Tried converting the two files (sky.gmt & skyboxi.gmt) to gtr format and have also tried to use a skyboxi lines from another track to no avail.

I would like to get this converted test it then see if I could get the ok to release it. (If I think It's worth It!)

Any help would be greatly appreciated. ( I know a lot of people would like to have this track.)

I know very little about converting rFactor to GTR2 but I do know you have to rename a lot of materials in order to get them to work.

Thanks GeeDee.
I have followed RacerM's tutorial.
So I have renamed & repacked the files.
I was just thinking today that I might need to convert some more of the gmt's to gtr2 format.
I still don't know why the sky & skyboxi will not show up in 3dSim program?????  
Even with a skyboxi from another working track.
Another problem may be with the textures format?
That would be a BIG problem, I don't have a DDS paint program. (and might not get one any time soon.)

You can get Paint.net free and loads of plugins and tools for it from their website You will be able to load and save DDS files.

http://www.getpaint.net/download.html