Teach Me about Blender for GTA5

I wanna to modify vehicles of a game named GTA5 and i was unable to find a way to import and export .yft, .ytd files in blender. I know that I can import them all as an .xml files but they are not exporing into .yft files.
If I import as .yft.xml and export as an obj, the collisions are also become the part of rendered model