Just a little pointer as i've just done an auxiliary belt and its tensioner on a 1.8T and cant see them being too different..
The front panel/lock carrier doesnt need to come off to change the serpentine belt, you can leave everything attached and unbolt the front panel, replace two of the bolts with some threaded rod and slide the complete panel forwards enough to access the belt and tensioner without having to distrub any water or electrical connections
I used two 500mm lengths of M8x1.25 rod but that was overkill, 300mm would be plenty
its all detailed in the haynes manual if you need any more info.
the only bit i found difficult was that one of the bolts for the tensioner was behind the fan, i managed to wedge an allen key into it though and got it off