Replaced Fuel Filter, now won't start

I just replaced the fuel filter on my 2000 Malibu.

Now, it won't start.

Did air get into the system?

Does it need to be primed?

The fuel pump is working, I can hear it humming.

Any Ideas?

If the Fuel Pump is working and primming, then the only suggestion I have is that maybe the Fuel Filter was installed backwards.

It can't be installed backwards. Threaded end on one side only.

Have you checked for fuel at the rails?

There's a shreader valve with a cap on top of the engine in one of the fuel injector rails that looks like the valve to put freon in the A/C system (like the ones to fill the tires with air).
with emgine OFF, remove the cap from the shreader valve, wrap a shop towel around it and give a little push to see if fuel comes out of it (same as like releasing air from your tires).
If no gas comes out then prime the fuel pump (key On engine OFF and wait for the Fuel Pump to run and stop) and check the shreader valve again.
Post back with results.

Maybe when he was installing the fuel filter he forgot to disconnect the batterys neg. if so maybe he shorted the fuse causing the fuse to blow or maybe the relay. First check the fuse if it not blown then remove the fuel relay and change it with the horn relay if the car start quick then just change the relay.