If you're a somewhat capable DIY'er you can probably DIY. All the parts you need to get to are right up front, but you should probably have the Benteley manual, or equivalent, for reference... and , of course the appropriate tools. The part is not expensive <aftermarket>, but getting all the air out of the cooling system after you do this easy swap wil take some time/effort. But it ain't a big deal; just takes some time.
What have you gotten for estimates for this repair from dealers or other service providers?