You should be able to do it yourself, but be careful not to leave the bars loose, you should be able to undo the bar clamps and rotate the bars forwards or back then re-tighten them in your prefered position, if your unsure of what to do then go to your local bike shop and ask them to explain how it's done, most will be happy to help out. Also look in your work shop manual and see if they have a diagram that shows the steps you need to take, it's one of the easy jobs.
Just had a think about this and Yes it's an easy job but not if you haven't done it before, what I meant was it's easy in the working on your bike sense but like anything you need to feel confidant in what your doing, so small steps, that way you will not bugger things up by trying to run before you can walk.