From the train station, go right and walk through the tunnel. Exiting you'll see the main road on the left (this is where you'll come from if you traveled by car), but you need to continue straight ahead and take the stairs that go down another tunnel (there's a sign guiding you to the “Marina”). Walk all the way down to the harbor, then take the path on the left and go up the stairs. Simply put, always follow along the left wall of houses! After about 50 meters you'll reach a small plaza, where you can see another flight of stairs going up and back into the town. Go up there and, a few steps after entering the “tunnel” between the houses, you’ll see the green entrance door for "Ai Pesci" on the left. Be aware that there are quite a few steps to master (as everywhere in the Cinque Terre), so if possible avoid big suitcases or organize help if needed!