Crown Victoria misfire, I believe it's the fuel pump.

We had done the compression test, all is well, It started with a misfire on cyl 3 so we did air filter, fuel filter plug and coil for 3. Then I scanned later and found misfire on 1,3,4&5. Fuel pressure test says it sits right at idle but drops to 30 or less at load. As when I get my misfires. I'm also getting purge valve code but it's always been like that. Any ideas?

2011 Crown Victoria police interceptor

Where would I cut in the trunk to replace easily?