Seeing as the fan above it must be an exhaust fan and the freshener is right under the fan, the fan sucks the hot air and on it's way toward the fan it gets freshened, making the surrounding area smell good.
its easy, just hide like ALL of your wires behind the plate that the mobo goes onto
use tape to hold it in place like blindviper did
i dont know how blindviper did it but ur gonna have lots of wires on the back as apposed to viper's 3 sets of wires