I did this exact deviation this past Christmas/New Year's timeframe (2015). The detailed instructions in the post are spot on, and the whole thing is super easy overall. Two things I would mention- 1. The Narita ramp agent (while nice and super helpful) was aghast that we were taking the train at that time of year. Said we'd NEVER get a seat. The trains were empty. So, if something special is going on you should still not have a problem... There's so many trains running. 2. Follow the instructions exactly when you get to the mall/Swisshotel area. Easy to get turned around/lost in the underground mall.
Sent from my iPhone using Tapatalk