Assuming it's a simple adjustment only, about the only part you might have to replace is the valve cover gasket. That's pretty minor.

Look for Walt Conner amongst all the hard starting threads.
Email him, stating that you need his valve adjustment instructions & your model# and he'll email them back to you.
WELL worth it!

When pulling the valve cover, you will also want to know if the studs for the rocker arms came loose from the head- thus increasing the clearance. A visual inspection and a quick check with a 10mm wrench will tell. Sometimes they loosen to the degree the cap comes off from between the valve and rocker. If the push rod is laying loose- let us know if it is bent and what else you find. In 2007 builds they discontinued the rocker gasket and used sealant. RTV or Right Stuff will replace the gasket in either case if you desire. Any problems reaching Walt -just let us know.

This video on You Tube will explain how to do it. But I agree with the other guys...get the specs. from Walt.
http://www.youtube.com/watch?v=tSyHlh9Ea4A