I posted this in the DIY section but figured it should be here too. Hope this helps...
1) Allow vehicle to cool down then raise using jacks or ramps.
2) Remove the undertray (approx 20 8mm screws)
3) Grab your 5 gallon bucket and place under AT heat exchanger.
4) Unclip hose as shown.
5) Slowly pull hose off heat exchanger. Coolant will begin to trickle.
6) Open hood and remove Coolant Reservoir Cap. Caution: drainage changes from a slow trickle to full flow.
7) Place hose back on and secure clip.
These next few steps are taken from the Bentley Manual:
8) Open Coolant Reservoir Cap and bleed screw.
9) Fill until coolant starts to emerge from bleed screw. This will either be the standard 50/50 mix or your own. For track purposes in the warm valley, I used 25/75 coolant/distilled water plus two 24oz bottles of Water Wetter.
10) Close bleed screw.
11) Fill Reservoir to lower edge of filler neck.
12) Close cap and perform following to bleed system. Bentley recommends connecting a battery charger. I didn’t have one so I turned most evertything off to conserve power.
13) Switch ignition on.
14) Set heater to max temperature and turn fan to lowest speed.
15) Press accelerator pedal to floor for 10 seconds.
16) Bleeding procedue begins and takes approximately 12 minutes. (Electric coolant pump turns ON and OFF automatically). Caution: Do not open reservoir cap while pump is on.
17) Fill coolant tank 100ml above MAX
18) Check for leaks.
19) Replace undertray.
That’s it. Again, using this method results in draining approximately 1.25-1.5 gallons. AT vehicles have a 2.23 gallon capacity. MT vehicles have 2.17 gallons. If desired, you can complete a full flush. This will require the removal of your FMIC and eliminates steps 4-7. Instead, after removing the FMIC, you should find the radiator drain plug. Open and drain. Then continue on to step 8.