jxzy, you can take bus number 6011 or 602 that will bring you to Anguk station 9000won (one way) and you will be almost in front of the temples. For me it took around 60 minutes (just the bus ride) but I did it only once (yesterday ;))
However, for such a short time I would rather spend it walking on the main streets to see the atmosphere of Seoul, perhaps in myeong-dong (or something similar)
cheers!
