The Bus and Train stations are just around the corner from the Caracol. From the train station follow the exit past the Bus station: follow the exit to the main avenue. Cross over the pedestrian crossing and follow the pavement around the Palacio de Congresos (the old tabacco factory - the building with the big chimeny) you are now in Calle Plocia. Calle Suarez de Salazar is the side street off to your left between the restaurant Atxuri and the little shop Cepa Gallega.
Look for the blue door with the yellow snail.