Yup, its right there on that map.., drive past immigration towards Saphan Hin, go around the bend at the end of the road (if you don't turn you go into the sea!), and come back around to where the stadium is. Should be a ton of people there.
They were doing it in Phuket too. I got a booster last week at Saphan Hin Stadium near immigration in Phuket Town. Simple enough - bring passport, queue. In / out in 20 min.