It's not for the feint-hearted. The fuel pump is capable of some amazing pressures, the connections between it and the fuel rail have to be done perfectly. It's an expensive item too - usually what fails on these things is the SCV (Suction Control Valve) which gets dirty and Nissan charge $240 to replace when you could just clean it. But even $240 is a whole lot nicer than the $4,000 that Nissan charge for the whole pump.