By beating a couple of 6-7 loss teams in the final two weeks? There are 10 or so teams ranked ahead of UW and USC that will remain ranked ahead of them as they also beat mediocre teams down the stretch.
BYU's chance to land in the rankings vanished when SDSU lost last week. If SDSU were ranked in the top-20 or so, then BYU could have another ranked win in their cap to attract some votes.