So go to the CM before getting in line?Not quite. All of you go up to the CM and you'll get a child swap pass. The family waits in line and rides the ride while you and the two-year-old wait outside the line. When the rest of the family finishes riding, they come out to wherever you are. You (and up to two of the others) go up to the ride, show the child swap pass and use the FP line to ride while the two-year-old (and everyone else) wait wherever you want. You do not need to use the child swap pass right away (you can generally actually use it anytime on your trip - but this may differ between WDW and DL).