I am pretty sure it's not a small job. A forum member here in Australia has carried out this mod. I don't know if he is still around. Search for forum member "saferisk".
His car got the cover of Performance BMW magazine. It's a 2007 E92 335i with some "mild" mods. The article says he did the CCC to CIC conversion himself. If you can get a hold of him, he is probably the best guy to talk to. The article obviously does not mention his forum username, but it is his car. There are other threads on the build, but this is what I found first.
Here is the link: http://www.e90post.com/forums/showthread.php?t=555104