Cut two pieces of cardboard from a box. Use the edges of the cardboard to corral the pool of paint. Then use the pieces to form a scoop, and lift the liquid back into the bucket. When most of the liquid has been cleared, get two more buckets—one with fresh water and one empty. Saturate the remaining spill with the clean water, then scrape and scoop it up with a fat spoon and put it in the empty bucket. Work fast and continuously, replenishing the clean water as necessary. Rent a carpet cleaner to follow up; just be sure to keep the paint spot wet until it gets there.