Link seems to be good to me too.
what is supposed to mean by
clear out FSW_PSW .TRC and .MAN files?
Clearing them out is just opening them with notepad, deleting the text inside, then saving.
Grant@DetailAddict's comment is extremely vague, but I think he means that if something did go wrong, there is a different way of reverting back to defaults. I would copy the FSW_PSW.TRC file to another folder like I suggest, that way if something does go wrong, you can try either way.
Current 2011 E90 335xi - Ordered 7/10/11 | Finished Production 7/20/11 | Delivered 9/3/11
On order 2015 ///M3 - Scheduled Production 7/14/14