How To Get There
Best Option is Flying

The City of Monterrey Mexico is the city to fly to. There is a major airport served by many U.S. airlines. The airport serves the three million people in the Monterrey urban area.
From the Monterrey Airport it is about a one hour ride to El Potrero Chico.
Many locals offer airport pickups for around $60 a ride with a stop at the grocery store. If taking a cab make sure to go to San Nicolas-Hidalgo, because there are two Hidalgo's in the area.
Driving
If driving a US car to El Potrero Chico you need both a Temporary Vehicle Import Permit and Mexican auto insurance. Your US insurance will not work down there and if you get in an accident without insurance you will likely end up in a Mexican jail at some point. Details on how to get a Permit when you cross the border into Nuevo Laredo can be found here at: Potrerochico.org