Dump the M1911 pistol and equip the M14 EBR, the one with the infra red scope
Pick up the claymores and set up the gun turret on the road just outside the pumping area so that it can sweep where the mofo's come from
Retire to where the car vacs are and kill the first wave picking off loads at distance with the infra red and finishing the ones that get close with the assault rifle
Set up a claymore defensive line at the back of the diner...whack the sentry gun out front and a claymore or two at the front door.
Then its just a matter of surviving 4 more waves whilst having to down helicopters and being targeted by predator missiles

I've only ever been able to do it online co-op and thats only on regular