So, brand new to this forum I typically work on Heavy machinery/Semis being as I'm a heavy line mechanic but today my boss brought me a 99 E350 and he needs the oil pump replaced.....
So does anyone have a guide or some reference on how to get to this without taking the body off... it's located right inbetween my firewall of the cab and hood underneath the fuel pump... From the looks of it it's apparently a giant pain in the butt.

 

Welcome to FTE!

Here is a link to an awesome thread on replacing the low pressure oil pump on a 7.3.

Duck Fan L Pump

But I do not understand the description "located right in between my firewall of the cab and hood underneath the fuel pump".

The low pressure oil pump (lpop) is on the front of the crank, that's the link above.

The high pressure pump (hpop) is located straight up from the low pressure on the front top of the engine.

Hope this helps.