Drive south out of San Diego on Interstate 5. This highway runs to Mexico. After crossing the border, continue onto a road named Bursátil, then continue onto Paseo de Los Heroes. Take the third exit at the roundabout onto Décima y o J. Sarabia, also called Avenida Independencia, to cross the Rio Tijuana and enter the center of the city.
Alternately, pay to park in a lot in the United States near the San Ysidro Border Station and walk into Tijuana.