fuel filter Audi 90

[Mark Zvolanek <mzvolane@sydney.ipex.com.au>]

Audi owners!
I attempted to replace fuel filter on my 1991 Audi 90 last weekend. But I   
did not get much done as I could not remove the hoses from the pipes   
attached to the filter. The end closer to the engine has rubber hose with   
some clamp, the other side going towards the pump has some sort of   
plastic like substance hose. No matter how hard I tried it would not come   
off. Haynes states to just remove hoses. I figured at least one of them   
must be removed.
What is the trick to get one off?
Mark