This would be an easy job if there was more room. The first step is to pull back the tensioner and remove the belt. Again, lots easier if there was more room. VW does have a special tool for this but I have always used a simple 10" adjustable wrench on the tensioner bail. This is done from below, you will of course also have to remove the belly pan if its still there.
With the belt off you will then have to remove the air filter assembly.
Now you should be able to see the tensioner pulley and replace it
With the belt off you will then have to remove the air filter assembly.
Now you should be able to see the tensioner pulley and replace it
