Minimum Requirements to be a GED teacher

Hello. Firstly, I would like to say thank you to LINCS for allowing me the privilege of joining this community. I have been a Certified Correctional Officer for eight years and a Certified Counselor for a year and a half. One of my most important duties is being the GED coordinator for our facility. You see, I received my GED in 1981 and I can completely relate to anyone who has difficulties with learning. Whether those difficulties are genetic or environmental, or a product of one's bad choices or a bad economy, they are still difficulties and if there is any hope that an offender will not return to the correctional system, they will have to have their GED. At our facility, we use outside teachers from a local technical college but this has been an issue for a long time as we cannot seem to keep them for very long. The offenders, or, inside students, have become very frustrated as they keep going to class but are unable to go for testing due to their hours are not able to be logged. Our solution of course would be to have our own GED teacher which brings me to my question. What would be the minimum requirements needed for me to become a GED teacher for our facility?

Thank you very much for all suggestions and advise.