2012 Hyundai Sonata Airbag Light is on in the dash.

I rear ended another car at slow speed with no damage to exterior of the car but the airbag deploy light came on in the dash. I took it to a dealership and the diagnostics was the restraint control module (RCM) was damaged. They told me this was common with a sudden jolt to the car. They did not have the part to fix it so when I return home from my trip I had my local mechanic install a new RCM but the light did not turn off. They informed I would need to go to the dealer and have software flash preformed in order to turn the light out. Is there another way to do this as the dealer is wanting to charge two hours of labor for this?