To test oil pressure, you remove the oil pressure sensor and attach an oil pressure gage(guy at Autozone does not know what he is talking about).....
Chiltons is half right....you use a fused jumper lead(all this is, is a jumper wire with a fuse holder in series) to test the oil level sensor......stick a 3amps fuse in the fuse holder, disconnect the harness to the oil level sender, and attach the fuse holder to the two wire harness.....your oil level light should now be off, whether the engine is cold or hot, it should be off....if it stays off, bad sensor......if it comes on, the wiring circuit is bad, or the cluster is bad(I think the wiring goes directly to the cluster)......