Pull a spark plug wire off. Put a screwdriver into the end of it and hold it close to the block. Have some one hit the key and see if a spark shoots from the screwdriver to the block.
Take the coil wire out of the distributor. Pull #1 plug, put your finger in the spark plug hole. Have someone crank the engine until it starts to blow air past your finger. Stop cranking, turn the engine by hand (breaker bar on the harmonic balancer bolt, or put the car in gear and push) until the TDC mark on the harmonic balancer lines up with the pointer on the passenger side of the engine. Loose the distributor hold down bolt, remove the clamp, cap and wires, disconnect the wiring harness. Pull the distributor straight up.
The following re-install depends on the engine being lined up as in the previous instructions.
To re-install, turn the distributor rotor to point to #1 cylinder position on the cap. The#1 position is about 11 o'clock if 6 o' clock is the front of the engine. Line the rotor up with it pointing at the #1 spark plug position on the cap and drop it in: you may have to twist the shaft some to get it to engage the oil pump shaft. 10* is stock for most 5.0s' 12*-14* is good for more pep if you are not into NO2 or power adders.
Remember that Non HO engines use a different firing order from HO & 351W engines.