Catch the first 13 bus of the morning and ride it to Gwanggyosan. You can't get lost, just follow the everyone else. You'll hike in the dark most of the way, so a headlamp, flashlight, or fully charged cell phone is a must. Otherwise, you'll find yourself lurking behind other hikers like a spectre. Once at the summit, climb the rope up to the rocky top and hunker down for the show. Bring a thermos for premix coffee to share with others. Dress warmly.
When the sun arrives, let the previous year go and cheer on the new one with hundreds of locals.