I still dont get it

I cant see how that part in the last picture comes off of the alternator and bracket and how to intstall another one without ruining it. I see now why the 240D one is different, the extra stuff on the turbo engine is in the way of putting the bolt in from the back. I think im going to have to just put it back how it was for now, and get a used alternator with the bracket still on it.