Coming from the subway, use exit five or six connected to the Coex Mall. Follow the Coex sign and you will come out at Millennium Plaza with the Coex Mall entrance in the back of the plaza. Hyundai Department Store will be to your left and CoexArtium straight ahead.
Take exit two and walk straight for about 15 minutes. You will pass Bongeun Temple on your right and soon after that you will see the Coex Complex on the right side. You can enter through North Gate or keep walking straight along the center to enter into East Gate.