I pull both lines from radiator start car and add fluid through dipstick at same rate as its pumped out(I forget which line it comes out of (drivers?). Shifting through gears -with brake on!!! every 5-10 second so have someone to help you. I use about 2 gallons - have a couple extra qts too!Good idea to flush trans cooler with solvent and blow out too. I've done this on ford,GM,dodge, volvo since at least 1985, easy to do. Pulling pan and changing filter is optional.