The easiest way I've found to describe PreCheck location to friends is come out of customs and immigration area, go past the regular security checkpoint there, past the signs for the Hyatt and the AA checkin counters and PreCheck are just beyond the Hyatt.
Everyone has you on the bag recheck. Easy to the left just as you exit the customs and immigration area. Just drop off if tagged through or there are desks to retag if necessary. There should be signs