They will tell you where to set up then they will come around and collect the money.
It is best to go Wednesday 2-5 and pay and reserve a spot, this is to get a good spot. You can also go and wait in line at the gate with the little building on Thursday and someone will be there to take your money. There will be a line of traffic so just get in line and also get there asap on Thursday morning if you don't reserve a spot on Wednesday. It's $8 a spot and like $3 to rent a table.
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