In order to enforce your judgment in Mexico, you will need to have a Mexican lawyer press your case there.
Here is what the US State Department says about enforcing your US judgment in Mexico:
"Enforcement of Judgments
There is no treaty, convention or other bilateral agreement between the United States and Mexico on enforcement of judgments. See the Department of State circular on enforcement of judgments abroad at our home page at
http://travel.state.gov. To request enforcement of a judgement from a court in the U.S., in Mexico you must retain local counsel who will initiate an action on your behalf requesting enforcement in Mexico. You may not request enforcement of a judgement pursuant to letters rogatory. If you are serving process, however, and anticipate an eventual enforcement of judgement in Mexico, see the discussion of this issue above, under service of process."
For this, and other information about US/Mexico legal issues, click on:
http://travel.state.gov/mexicoja.html