Aux Tension Pulley Help

Evening all found a noise coming from the engine bay found out the auxiliary tensioner pulley is nakerd so going to give it a blast on changing it but have no idea on how to tried searching but can't find anything apart from front bumper of put into service position remove old bolts take of and replace with new. Question is how do I put it in service position I no how to take front bumper of but apart from that unsure also what tools do I need for the job. I have 2.0tdi blb
Thanks in advance
Ash

Ok cheers for I'll have a look when I pick the park up later I'm going to replace the belt aswel but is there any other bits worth changing and yer iv seen a lot of people writing that they moved the front end about 6 inch forward without taking it of.
Thanks
Ash

what a pain in the **** that was a 5 hour job in total. couldnt work out how to put the front bumper into service position so i left it on.
First got the car on some ramps
un hooked the battery up
took the tension of the belt and removed

took the two bolts holding the alternator on and removed power cable at the back (had to use a bar to get alternator out as it was in solid)
took the bolt of which was holding the wheel on the tensioner so i had some more room to take out the tensioner out
removed tensioner


Then repeat these steps backward but when the belt is lined up and the wheel is on the tensioner you need to removed the bin. this was the hardest bit, the best way i found was to go under the car and smash the pin through the housing careful not to hit the power steering pulley
and the start her up and is running great
even took it for a polish