3.0 TDI Poly V Serpentine Belt & Tensioner Replacement

[snapdragon]

Well folks, idle has sounded a bit noisier than usual outside of the car the last few days. I looked under the bonnet and saw that something had leaked at the front and was splatted around by the poly v belt. It didn't smell of coolant or oil, so jet washed it all off and went to work. Upon arriving, same again. Not coolant, not water pump, seems to be the belt tensioner has blown and it's damper oil leaked everywhere, but not 100% sure, so will clean off again tonight.

New belt ordered.. Was £10 this morning, now £18
https://www.amazon.co.uk/gp/product/B00FC4L774/

Will order new tensioner when I'm a bit more sure...
http://www.ebay.co.uk/itm/391298142750
Never heard of them, but INA is the OE and they make them for all the more expensive brands such as SKF, Gates, Audi, Meyle, FEBI etc...

Has anyone else changed the belt and or tensioner on a 3.0TDI? and if so any advice?
I have the Audi PDF but not sure whether the front end really needs moving forward to lock carrier forward position etc...