I just retrofitted a fbmfsw and cruise control stalk to my car yesterday, instead of buying a new bottom cowl i just cut the existing one and it worked out perfect. the way i looked at it, if i made a balls of it, i was going to be buying a new one anyway. I used the following guide and it really was simple - http://www.audi-sport.net/xf/threads/dis-and-cruise-done.177459/
Once you cut out the cruise control section just use a file to level it out enough to fit the stalk.