It is very easy to go to Santa Ana volcano by yourself. You do not need to book a tour. I stayed in the previous night in Santa Ana. There is a bus station in town to catch the bus to Santa Ana volcano. Out front is a security guard with a gun, don’t worry, they see everywhere. As I was approaching the bus station, he was waving to me. I must have stood out and he knew that is there I wanted to go. Inside, you buy a bus ticket, less than $2. There are a couple of shops to buy water and snacks. Pretty soon the room filled up with other tourists going to the volcano. Everyone gets on the bus. Don’t worry about where to get off. The bus driver knows. Everyone gets off. Walk up the path a little ways. There are English speaking guides, you pay $3 to the guide. Then to pay $5 entry fee. Walk to the volcano. Half way up is a man selling homemade ice cream bars. Amazing views. When you walk back down to get the bus, up the road a little bit, that leaves at 1pm to go back to Santa Ana if that’s where you’re staying.