You should be able to get away with just jacking up the front, higher on the passenger side to angle the drain plug to the lowest point. There's only 2 screws holding the FMIC and you just unclip the pipes and it should come out. The drain plug is blue and green so it's fairly obvious.
If you absolutely need to jack up the car on all 4 corners, I typically jack up one of the rear side jack points high enough so the front raises, stick a jackstand on the front. Then you should have enough clearance to reach the front jack point under the engine, it looks like a rectangle with rounded corners, about 4"x1.5" dimensions, it also has a bolt in the middle of it. This will raise the other front side, to which you can put another jackstand. and then from the back, i jack it up from the differential gear box. But i don't think you need to jack the rear end for a radiator flush.
The radiator took about a gallon in total fluid. I did a 50-50 mix with distilled water, so I only used 2 quarts of antifreeze.
Hope this helps!