I don't know either - I guess you mean a motor start/run capacitor in a big can. This is what I would do...
First find the capacitor - with the AC power disconnected - Put a tape on each wire with a number on it - draw a picture with the numbered wires running to each connector - take a digital 'photo.
Carefully short each terminal of the capacitor to every other terminal with a screwdriver blade to remove any charge that may still be held.
Pull off the connectors - remove the old capacitor - fit the new one - put the wires back according to the drawing.
Peccavi, October 2010
