Turn off power to the outdoor unit via the electrical disconnect or breaker.
Remove the electrical panel cover of the air conditioner by taking out the screws that hold it to the unit. Verify that the power is off with your electrical meter by setting your meter to measure voltage and touching the probe ends to the lead side on the contactor. This is where the wires enter the unit. You should read no voltage.
Use a screwdriver to ground the terminals of the capacitor to the metal cabinet of the air conditioner. This will discharge any stored charge within the capacitor. Write down the colors of the wire, where they come from and which terminal on the capacitor they connect to. You can also check the current wiring against the wiring diagram located on the inside of the panel cover.