There are several very good youtube videos on the subject, by Googeling you can probably find your exact jack. here's the aluminum Pittsburgh from Harbor Freight:
What it basically boils down to is opening the valve by turning the jack handle all the way counterclockwise, removing the oil filler plug, filling the reservoir with oil, and pumping the handle (still open) a few times to clear the air. A quart of Jack oil is $5.95 at Advance or O'reileys.
