I just suck what I can out of the rez with my slightly modified flavor injector (looks like a BIG needle) and let it trickle back down and keep doing it until gravity won't effect it any more..
I picked this up at Wall-Mart and clipped the sharp tip off..
Call me crazy or just a greahead, but I take one loose line, put the other loose line in your spill tank and blow in the other one.. That pushes a lot of it out, just DON'T SWALLOW any of it. I know automotive coolant can kill you, no lie.. I forgot what the difference is exactly. You may have to take the radiator apart individually and drain it. But if the lines are drained, 10-1 the blocks are drained as well.
How much of your system is liquid cooled? Just the CPU? CPU and GPU? and yes, need pics and details.