Does anyone have or can you pnt me in the direstion of a step by step guide to changing the Haldex oil and filter. Also I believe it's a good idea to change the differential oil as well but east to get mixed up with what's what when daringing/re-filling. Don't want to get it wrong as I beleive it can be expensive. Also there is a Locking tool, what does this do and where is the best place to get one? Car I am going to do is a 8p 2.0 TDI Quattro 2007 model.