Lantau island is the big island between Chek Lap Kok Airport and Hong Kong Island. From Central, you can take the subway (HK$23 pp each way) or you can take the bus. In order to get to the cache, you will need to take the #23 bus from the subway station. Fare is HK$16 pp each way every day except Sunday when it is HK$25. Make sure you have exact change and there is a 7-11 nearby if you need to make change.
The web page of the new cable car can be found at http://www.np360.com.hk/
It doesn't cost anything to get to the cache and this is a location that won't take you long to see, I spent about 2 hours here.