Step One:
Walk into a shop and explain to them that you would like a "Belgian Haircut." Don't be surprised when they don't know what you mean, for, after all, you're in Belgium, so shouldn't all of their haircuts be Belgian. Hand gestures work well here. Indicate a shortening of the top layers of hair while making long sweeping, waving, flowing gestures from the back of your head. Indicate (and I don't know how you'll do this) that you'd like your neck to be kept warm by your hair.
If you're really having problems, remove, from your pocket a picture of Tom Boonen. At this point they may cry "Tom BOONEN (long O), or even "Tomeke" (pronounced tom-eh-ka.)
This is where things get decidedly simple. You are now in the hands of whichever barber/stylist you have chosen. Choose well friends, because as we have seen, you can't just walk in to any shop in Gent and expect to be greeted with charming, beautiful stylists. We thought one was a woman, turns out he wasn't.
Close you're eyes. Savor the moment. This is going to be good.
Examine the back of your head. In the case that we have here, I'm not going to lie, it looks a little short for my tastes. I would prefer something that not only slaps at the back of my neck, but the necks and more importantly faces of riders around me. But who am I to judge. This looks pretty damn good. A bit of fluffing and who knows what will happen?
Smile, be proud of your new found heritage. You've earned it. If you now have something on the back of your head that would make your mother say something like..."Oh, Peter...what have you done.." Then you've done well.