I've gotten quite a few questions lately about upgrading OBIEE from older versions to 220.127.116.11: how to get it done, what are the steps, etc. In other words, "Floyd, how are you getting it done?"
Well, the honest-to-goodness truth is...I follow the instructions of people who are smarter about it than I am. It's a practice I follow quite often. Albert Einstein used to say that he never memorized anything he could look up. As a lazy guy, that sounds really good to me; it's worked out well.
So, in terms of steps for upgrading OBIEE to 18.104.22.168 (or anything else regarding OBIEE, for that matter), I look to the very bright people at Rittman-Mead. You can find all you'll ever want to know about the upgrade here.
Google (or Bing or whatever your search engine of choice happens to be) is your friend.