Mike,
I attended classes at Dallas County Community College. I believe there are two ways of going about this. The first would be a case by case basis where a student would set an appointement, meet with the school's chief flight instructor and present documentation that he/she passed the FAA written like Cessnaflyer has said. Second would be credit by examination, where the student would pay some sort of admin fee and be given the class final exam, which in my experience is essentially a mock version of the FAA written.
Here's the number for DCCCD's Aviation department, in case you want to call and get some info straight from the horse's mouth. It's close enough to Terrell. 214.860.8566