Several keys did not work
Using the step-by-step iFixit guide it went off without a hitch.
A small matter, but the first major step after removing screws was to unplug the power ribbon. I was very reluctant to simply pull, especially after reading on other sites that there was a locking bar which I couldn't see. Just add a line about simply pulling being ok would have relieved some stress. Otherwise the guidance and photos were excellent.