From Highway 680 (north- or south-bound) exit at Treat Boulevard and drive east approximately 1.6 miles. Turn right on Winton Drive and right into the parking lot.
You may also get turn by turn directions from Google Maps.
BART (Bay Area Rapid Transit) has a Pleasant Hill station located approximately 1.5 miles west of Carondelet at the corner of Treat Boulevard and Oak Road. The County Connection #11 bus runs from Pleasant Hill BART and makes a stop at the corner of Treat Boulevard and Winton Drive.