Fuel pumps on Micras are one of the few items which give trouble. You could expect the fuel pump to be giving trouble by now if its a 1994 car.
The fuel filter is easily changed. It is held on to engine compartment bulkhead by a spring clip and there is just one hose in and one out - easy to change.
Fuel pump is in fuel tank. To access you need to remove the rear seat. Depressurise fuel system first by removing fuse for fuel pump/system and trying to start engine with key. Unscrew fuel sender unit on top of tank. Fuel pump is immersed in the petrol. Not too difficult to change.
JD
December 2008