Yea, you'll have to open up your ESI to install the new chips. In principle, this is pretty easy. However, I did run into a couple of problems. One was that the screws on the back were so tight till I thought I might wind-up stripping them before I got the thing opened. Secondly, the chips won't come out easily. You have to use a tool that comes with the upgrade to pry the old chips out. Just pull a little on each corner, and eventually the old chips will pop out. This takes some patience.
I don't remember doing any software fiddling. I think there may have been a short initialization process, but I can't recall. What ever it was, it must have not been that big a deal or I would have remembered it (I hope).