We went from Chugchián to the lake by "Camioneta". We walked down to the lake from the border of the crater then back up. After that we followed the trail back to Chugchilán (Google maps call it Chucchilán, go figure). This is a very nice scenery area and it is not a difficult hike. Highly recommended.
The "camioneta" costs $25 per ride, not per person. You can arrange it with you hostel. I stayed at Mama Hilda Hostal. The way point for that is on the map.You will have to pay $2 to enter the lake area if you are a foreigner. Ecuadorians have to pay too but it is cheaper.Direction: It is better to go from the lake to Chugchilán because this way you go down, and therefore it makes it easier.The trail does not require a guide but it is not well marked, there are several forks on the way with no signs. There are, though, "some" people on the way, but no many, and you can ask for directions . I felt that people were generally very friendly to tourists in this area and in Ecuador in general.You will cross some small villages and around these places be aware of dogs. They are not a real concern unless you suffer from cynophobia, because they come in packs. If they run up to you, just make sure they see you grabbing a stone from the ground or keep your guard with you walking stick if you happen to carry one