filler neck is dead easy, 3 screws behind the trim round the filler opening, screw in inner arch and big rubber pipe to disconnect to tank and a smaller pipe for the tank vent. pump is also easy, bracket held onto car with a couple of nuts.
Take the pump off and check the inlet side, some of them have a little filter in, if yours does its probably blocked. also remove the accumulator/reservoir and clean this out with fresh fuel. Take out the lift pump while you're there, its under the round metal flap under the rear seat.
While the lifter pump is oiut have a good look in the tank, shine a torch in there see if you can spot any crud. drop a speaker magnet on a string in there in and drive it for a week, pull it out and check for rusticles. clean it off and repeat till it comes out clean.
