We are just too frugal to hire a guide (it's US$ 25 I suppose) and so we get up the next morning, get ourselves some supplies in the supermarket around the corner (make sure to bring enough water) and head to the bus station.

You can take any El Espino bound bus and get off after around 30 min (US$ 0,40) at the tiny village of La Playa. From here it's only a short 10 min walk to Rio Tapacalí and Somoto Canyon. Once you reach the river, the only thing you basically have to do is to follow the stream. Thats not too hard is it? I mean in the end it's a canyon which limits the number of directions to chose from to quite manageable amount.

We did the hike in February and didn't have any problems with the water level. Nevertheless, Somoto is still a canyon and therefor it might be subject to abrupt flooding, especially after heavy rainfall. Due to that the canyon often closes in October.