I was looking at taking my injectors for a vapor test, I'm getting some smoke, anyway the only tool you see advertised is a 27mm socket, but i cant see the base of them or even remove the black rubber seal. The injector also has a 15mm flat is that the way to remove them ?

I was also looking at draining any water from the fuel filter, is there a drain plug at the bottom its all hidden away its a 2.5 TDI V6 quattro B5 facelift 2001. Any advice much appreciated