There are links on the Fermacell site for youtube videos that show the whole process, if you use the steel preformed stud system it looks a doddle, you can download the Orange Book from the link i gave you, my installation is a nightmare as i made the mistake of using Celcon Solar blockwork on the internal walls and trying to get a fixing is a mare, as you can't apply any weight on the screws or they just start rotating, so for any chance of a decent fix all the battens have to be re machined to get them parallel straight and square then lubricate the screw and softly softly till it hardens up but no more.
Regards
Mike