Not what your friend needs to hear I'm sure, but It'll be either luck or hard work that will get the shot most of the time. I bumped into a couple of the Giant Alpecin riders at Amsterdam airport last year just by chance, and many people on here will have similar stories of decent luck... one CC member met Stannard and Froome last week as Sky happened to be staying in the same hotel in Spain during La Vuelta. So right time, right place is key.
The hard work route is, well, harder. Go to a race stage start or finish, hang around a team coach at warm up / warm down, and if you're patient and polite you can bag someone. Hopefully the rider you want, although some are easier than others, demand and personality play a big part.