It's not a real difficult job overall ... maybe just a bit time consuming if you've never done it before. You'll need to remove the timing belt, power steering, intake/exhaust manifolds, various sensors and wiring, as well as some other odds and ends. If you've got a service manual and another set of hands, you should be able to do the job on your own. Just take your time.

Depending on mileage and wear, you may want to take this opportunity to do some maintenance if it's needed (valve adjustment, belt replacement, gasket replacement, etc.).