How do I get from San Diego Int.Airport to the airfield in Tijuana?

There is a bridge (CBX) from San Diego to Tijuana int. airport. You don't even have to be outside in Mexico

You have to cross the border....From San Diego's airport, take the 992 bus ($2.25) or a cab (about $10) the 5 minutes to Santa Fe train station and take the Trolley to the border to walk across. By Car -- To drive to Tijuana from the U.S., take highways I-5 or 805 S. to the Mexican border at San Ysidro

You need to use Uber or lift (taxi). With public transport it will take forever as the San Diego public transportation system is very bad.