For the descent you can either take the cog railway back to Alpnachstad or if you prefer the cable car will take you back to the suburbs of Lucerne (from where you most likely would have made the trip to Alpnachstad).
Alpnachstad can be reached from Lucerne by train or if you're feeling adventurous there is a lake steamer that takes around 90 minutes.
When to travel
The cog railway runs daily from 8:20 until 4:50 between May and November. Outside these months you'll have to use the cable car. Also bear in mind that this railway is totally dependent on weather conditions.
Passes and Tickets
As this is a private railway the standard rail passes do not cover the journey. Unfortunately on this route there are no discounts unless you have a Swiss Pass in which case you'll receieve a 50% discount. Tickets are available at the base station in Alpnachstad.