Here's a page where you can download someone's GPX file:
http://www.gpsies.com/map.do?fileId=onrhhcwsivbhffhnThe northern half of that route is the 6 Foot Track, but forking off before reaching Explorers Tree, and going instead through suburban Katoomba to the station. The southern half of that route is the Devils Hole Track, though the uploader went along Stuarts Road rather than along Valley Road as I usually do.
If your aim is to get to the railway station, I think going via Explorers Tree might be the fastest way, because it's fairly level from there to the railway station whereas the other routes cross a valley. Especially if you are finishing after dark, the 6 Foot Track to Explorers Tree is easier to do at night than the Devils Hole (although I have done the Devils Hole Track at night by the light of my phone's torch - progress was very slow but it was a great experience).