From Leonardo da Vinci – Fiumicino take the Leonardo Express (every 30 min) to Termini train station. At the train station the B blue subway line, direction Laurentina and get off at the Cavour subway stop and walk in foot Cavour street until you reach on your right side vicolo delle Carrette, or from Termini station take the bus nr.75 and get of at 4th Cavour stop.
From Ciampino airport take the bus shuttle Terravision service to Termini train station, or the bus that goes from the airport to Anagnina were you have to take the subway until reach Termini train station were you get of. (Low cost solution)
By car from every Italian highway get of at GRA. and take the exit direction Roma Centro and then drive in Termini train station direction; once in front of it (Termini) take a left and get on Cavour street and keep driving till you reach vicolo delle Carrette which is almost at the end of Cavour street on your right side.