I have read through the manual but I really cannot find the answer.

I have gone through the menus ( after switching them from the owners native German to English ) and I cannot find the setting.

Can someone please point me to where you switch the focus acquisition from the shutter to the "back button" on a 550 D.

I had a similar episode a while back where the focus was set to the back button on another persons 550D body and could not find how to change it but it wasn't a major concern at the time but it is now.