[btwilson86]

From what I've read and done on other cars is to jack it up to about 35-45 degree angle (if possible; hills help with this). Pop the radiator cap off, turn the car on and the heater on full blast, and let it run for a looooooooooooooooooooong time. You should be seeing bubbles coming up at the radiator cap, and as long as your not revving the motor or anything, your coolant loss should be minimal. Just bring some premixed coolant with you because your coolant level will slowly drop as the air escapes.

I've never done this on a Supra cuz mine hasn't worked long enough for me to be able to, but it should be as I described. The greater the angle the better because of the height of the heater core versus the top of the radiator cap.