Hey fellas, is it possible to replace the entire wiring harness, or in other words how hard is it??

let me know.... u guys know the help is greatly appreciated!!!

 

Which wiring harness?

 

It is the harness that runs through the driver side fender to the fuses and so forth.... like the maine harness. I was wondering if it was possible to replace because when i start my car it dies every time because my fuel pump fuse blows. I have tried to fix it but i cant find which is the wire that is bad. please help!!