How do you replace a fuel pump on a Volvo s80?

To replace the fuel pump on a Volvo S80, first, disconnect the battery and relieve fuel system pressure by removing the fuel pump relay and starting the engine until it stalls. Next, lift the rear seat to access the fuel pump access cover, and remove the cover. Disconnect the fuel lines and electrical connector from the pump, then remove the old pump from the tank and install the new one. Finally, reassemble everything in reverse order, reconnect the battery, and test the system for leaks.