I can't find my serpantine belt diagram can someone provide one? I bought the kit on blauparts and it came with a tensioner plus belts but unfortunately I don't know the routing of the three belts. I drive a 2001 1.8t quattro

 

It's in the timing belt DIY. Obviously just stop short after the belt tensioner. I'm not sure if there's room to do it without going to service position (though if you do have to go to service position, don't bother disconnecting the radiator as you don't need THAT much room). But check how to do the serpentine belt tensioner stuff in that DIY and see if you can reach it from the top or bottom. If so, do that.