Two big adjustable spanners thats all you need to do the fuel filter one nut on the filter to hold tight the other to undo the union its simple mate just watch fuel and pressure don't undo the union too fast at least let some fuel and pressure escape for ten minutes. I usually have a smoke when doing this job

Remember there is a washer at one end dont loose it or just reuse the old one if its in good stead.
A plastic bucket to catch fuel dripping is not a bad idea! At vag there only about £10 or less?
Also the filter is directional i.e flow of fuel towards the engine it will have a big arrow stamped on the filter!
If its a 8V one end might be just a clamp and pipe instead of union bolt you will know soon as your under that car.