There are a few routes your friend can take.
1) become a le leche leauge leader
2)work with breastfeeding dyads (mothers and babies)
3)take a course through a college or continuing education department on breastfeeding
the only way to become a certified lactation consultant is to sit for the exam that is given every year onthe last monday in july. the test costs between $400 and $500 depending on whne you regester for it.
If you have an associates degree in anything, not necessarily nursing you have to get 4000 minumum hours of teaching or assisting dyads to breastfeed.
If you have a bachelors degree you need a minumum of 2500 hours of teaching experience.
there are "alternate pathways " as well that make you elligable to sit for the exam.
Also check out LACTNET. great digest that is for medical professionals that keeps everyone up to date onthe new stuff in lactation.
also as previously posted, check out the IBCLE website for more specific info! good luck