what is involved with this process… meaning what does it exactly test for and what has to be done to complete the test?
anybody:(
To do a leakdown test, you need an air compresser and the leak down gauge. It screwz in where the spark plug would go. Make sure the engine is at TDC on the power stroke (all valves closed). Then you turn on the air and let a certain amount of presure into the combustin chamber. (Im not sure what psi, but it isnt too critical). The directions should say. Now that there is presure in the cylinder, you want to check for leaks. Take of the radiator cap and look or bubbles, this would indicate a cracked head or blown head gasket. If you hear air leaking when you put your ear up to the oil filler on the valve cover, your rings are worn. Now put your ear up to your tail pipe. If you hear air excaping, your exhaust valves are burnt, or not seating well. I think this can be checked with the intake valves by puting your ear up by the throttle body. Nowdo this for all cylinders remembering to rotate the engine so your at TDC for each one.
Hope this makes sense and helps.
Brad 
yeah, makes since man, thanx