Firstly, your friend needs to decide which programme/slot he/she wants to aim for; which would attract the right audience to hear the music? E.g. breakfast show/afternoon or evening slot? Then find out who is the producer of that programme and personally visit them taking along a demo of your work - visit them as many times as you need to to show you are serious and determined. Just blindly sending off tapes/CDs to radio stations rarely works. If your friend is genuinely talented and has a Unique Selling Point, this tactic can work. In fact, in the current 'find-a-star' climate inspired by the likes of Pop Stars, local radio stations and newspapers are more likely to give your friend a chance (listen to their work at least, if not actually play it on the station) as, if you display real talent, they will want the publicity that discovering a 'star' will bring for themselves too.