Changing the EGR cooler is a difficult operation. There are many tricks to doing it. Most dealer techs who have done several can do the operation in a few hours. For a weekend warrior, I would plan on the whole weekend. On our website, we have a link to factory repair manual information. And of course, we offer all the free advice you can handle.
You might want to check out our ever growing dealer network. There might be a repair facility near you.
Good luck!