| Mate there is a small bolt and a v shaped clamp between the two fuel pipes that holds them in place.
When you have undone the seat and removed it from the tank, raise the rear of the tank up using a piece of wood, (i find a 4" skirting is ideal) then undo the bolt. You can then pull out the two pipe ends and the fuel will stay in the tank! You might get a little drop coming out the pipes but no worries. | 
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