You usea 3/8" ratchet (the square part) to remove the drain plug. About 2.5qts will drain out. Then top it off - USE ONLY HONDA OEM ATF-Z1 FLUID. If you don't, you will be replacing the trans very soon (due to failure) because all non-Honda trans fluidshave incorrect friction modifiers for a Honda trans. After topping it off, start the car and go through all of the gears. Then shut it off and remove the drain plug and drain again. After draining the 2nd time, top it off again with OEM ATF-Z1.