A number of bus lines operate from the Highway Bus Station (also know as the Aung Mindalar Bus Station) in Yangon to the town of Kyaiktiyo and Kinpun which is a town 10km (6 mi) from Kyaiktiyo right at the base of Mt Kyaiktiyo. You can usually organise the bus from the reception where you're staying. If you want to see the Golden Rock then do not get off at Kyaiktiyo (except in wet season, when you will be transferred to a pickup for the leg to Kinpun), disembark early at Kinpun, if in doubt tell the conductor you want to get of at Kinpun, their English is limited but they should be able to tell you when to get off. The first bus leaves at 06:30 and then go at hourly intervals until 14:30 (maybe later in high season). The fare is MMK8,000 and the trip takes 4½-5 hours.
photo by @sevenviaggi .