"If you are replacing the pump or rebuilding the engine"
Ok,,, since you did not mention this being the case I would have thought that one of the methods ( high pressure , or low pressure ) would be the one used...
"The drip method" is much less work... and if you don't have the high pressure tools it is still doable for the average mechanic... and shown in the shop manual...
Most of my " searching " is done in my paper printed MB manuals... so much faster than my dial up connection for seeing stuff.... and you run across a lot of stuff which you don't even know to ask about with a CD or things like that...