It will be time consuming, but not terribly difficult to do.
Basically the turbo comes out and you need to loosen all the intake manifold bolts enough to lift the front of it to get the o-ring out and the new one back in.
Might be a good time to consider an egr delete install if you don't have one on there yet (and can install such a thing).
I have directions posted for turbo removal/install and intake manifold removal/install that can be found by clicking on the "step by step egr and oil cooler replacement" link in my signature line. In that thread, I also have some notes about getting the exhaust all lined back up post repair (which can be more difficult than anything else..if it so decides to be).