I have no time atm, to explain. Maybe within few hours but not sure.
Check:
http://www.drgeep.com/
BTW I think best way to learn "how to use magnet" is "try again if fail".
Select object which you want denform, on menu "object" choose create magnet. translate/scale rotate determinde direction of deformation, determine area of deformation. Thats all. The rest is time which you must spend before obtain required effect :)