I did a couple a while back, dead simple to do. The pipe I used was actually off a chlorination plant from a water treatment works, meant to be for transporting neat chlorine, they only lasted a month with petrol.
Ended up using PROPER fuel pipe.
Unscrew the Mercury fuel connector, the black pick up pipe then unscrews from the tank, replace pipe then feed the pipe back through the small hole and screw the pick up back in to the tank
I put some covers on the outlets too to stop them filling with sea water when not in use.