thanks for the info, how do the tank straps undo? don't really fancy having a look until i've got the replacement pipe.
Pipe was about £17 inc VAT from VW and the straps just have an 10mm nut either end iirc. just make sure the tank is supported when you undo the straps (maybe with a plank of wood on a jack) and don't break the straps. Then lower the tank about an inch and should be alright.
Remember that the weight of the tank may shift depending on how much fuel is in it so just take your time and make sure everythings secure and level when undoing the tank straps