When replacing the upper case, after you've installed your new hard drive, make sure you remember to RECONNECT the trackpad connector. I forgot to connect it when I put the computer back together, and had to take it apart a 2nd time in order to fix my mistake. Other than that I had no problems with this upgrade thanks to the detailed instructions offered here . Thanks iFixit.com!
You can see photos of my upgrade process here if you are interested: http://www.flickr.com/photos/judahs/sets...