Chatelet-Les-Halles is served by RER lines A, B and D and Metro 4, 1 and 11.
The Halles car park is ideal for reaching Massage Concept by car. When you leave the car park, take the elevator on your right and go up to 0. Exit the Rambuteau door on the right then take the 1st left then the first right. Allow 5 minutes from the underground parking.
The Sebastopol underground car park is also a solution, accessible from Boulevard Sebastopol (one-way, from south to north). Once parked and brought to the surface, walk following the flow of the vehicle then take the 1st left onto rue de la grande truanderie. You are there. Allow 3 min from the underground parking.
Note that the area is pedestrian, there is no parking space in the street.