Need a diagram of undercarriage of 2003 Chevy Malibu. Need to replace fuel pump inside the gas tank not sure how to do it.

RELIEF FUEL PRESSURE, REMOVE THE FUEL CAP. THEN REMOVE FUEL PUMP FUSE AND START ENGINE, LET ENGINE IDLE UNTIL IT DIE OUT FROM LACK OF GAS. THEN CRANK ENGINE OVER FEW MORE TIMES MAKE FUEL IS OUT FUEL LINES. DRAIN FUEL TANK.SAFELY RAISE SUPPORT VECHICLE ON JACK STANDS.MAKE SURE VECHICLE SITTING ON SOLID LEVEL GROUND.REMOVE PART OF THE EXHAUST SYSTEM.THATS UNDERNEATH THE FUEL TANK.LOOSEN THE HOSE CLAMP THAT SECURES THE FUEL FILLER NECK HOSE TO THE FUEL TANK AND DISCONNECT THE HOSE FROM THE TANK. IT EASIER TO REMOVE THE FUEL TANK WHEN ITS NEARLY EMPTY, BUT THERE IS NO FUEL TANK DRAIN PLUG, SO IF THERE IS STILL LOT OF FUEL IN THE TANK, SIPHON OR HAND PUMP THE REMAINING FUEL FROM THE TANK THROUGH THE TANK FILLER NECK PIPE. DONT START THE SIPHONING ACTION BY MOUTH, USE SIPHONING KIT YOU CAN BUY AT MOST AUTO PARTS STORES.LOOSEN THE HOSE CLAMP SCREW AND DISCONNECT THE EVAP RECIRCULATION HOSE FROM THE FUEL TANK. DETACH THE ELECTRICAL CONNECTOR FROM THE SIDE OF THE EVAP CANISTER AND DISCONNECT IT SET THE HARNESS ASIDE.DISCONNECT THE QUICK CONNECT FITTINGS FOR THE FUEL AND EVAP LINES.SUPPORT THE FUEL TANK.YOU CAN USE FLOOR JACK BUT PLACE A PIECE OF PLY BOARD SO THE FLOOR JACK LIFT SADDLE WONT PUNCTURE THE FUEL TANK.ONCE FLOOR JACK IN PLACE UNDER TANK WITH PLY WOOD ON LIFT SADDLE JUST RAISE LIFT SADDLE UNTIL IT TOUCH FUEL TANK. THEN REMOVE THE FUEL TANK STRAP BOLTS AND REMOVE THE STRAPS. LOWER THE FUEL TANK ENOUGH TO ACCESS THE TOP OF THE TANK DISCONNECT THE ELECTRICAL CONNECTORS FROM THE FUEL PUMP FUEL LEVEL SENSOR MODULE AND FROM THE FUEL TANK PRESSURE SENSOR AND LOWER THE FUEL TANK REST OF THE WAY. IF YOU HAVE ANY TROUBLE YOU CAN BUY HAYNES REPAIR MANUAL AT ANY AUTO PARTS STORES. MANUAL WILL ALSO GUIDE YOU THROUGH THE PROCESS.

First, put a jack up under the fuel pump. then remove the two straps that hold the fuel tank or their might be a skidplate you have to remove first. when removed, slowly let tank down slightly so you can get to the fuel lines. there should be two lines and one hose. there might be more, if so just remove them. then remove the filler neck hose clamps and pull the hoses off of the neck where the gas goes in. then there should be one or two connectors. after that it should be safe to lower and set on the ground. then remove the fuel pump by either unscrewing a cap on the top of the pump or sliding a ring around until it comes off. then pull the old pump out and put the new one in. i recommend a fuel pump assembly over just the pump because the assembly wires become corroded or brittle and will sometimes be the reason your fuel pump doesnt work. install is reverse of removal.
P.S. check under your back seat or in the trunk under the carpet to see if you have a service panel for your fuel pump. if so then just take that off and you can pull the pump out without dropping the tank.