1991 cut access panel fuel pump buick park ave

DaveJm i need to cut an access panel in 1991 buick park ave. I can handle the cutting part. BUT WHERE DO I CUT? I looked up a replacemt gas tank & I KNW WHAT IT LOOKS LIKE. NOW I CAN DROP THE TANK DOWN ABOUT 3" - 4" & use a side-grinder in a jig i can make out of wood to limit how far the blade drops from the jig. AFTER CUTTING HOLE, I CAN USE SAME CUT OUT AS DOOR. MOUNT THIS ACCESS PANEL by hinge & use aluminum strip as door stop. Seal w/ SILICONE CAULK. QUES IZ WHERE IS FUEL PUMP ?

I'm so sorry; I couldn't possibly comment on a question like this; my focus is on factory equipped concerns and vehicle characteristics / diagnostic and repairs. Modifications are not my forte. I'd consult a local shop near you that could possibly give you advice.