This guide was great — I successfully upgraded my hard drive (6TB WD Green) and replaced the fan due to continuous warnings about over heating. The fan replacement required removal of the entire unit from the white enclosure and with some careful examination it is clear how this all comes apart and fits together… would be good to have a guide that walks through all the steps involved in doing a fan replacement since that seems to be a common problem. I am now happily using my new 6TB, cool (due to new fan) device.