You got to have the BCM cleared with a Scan Tool, not a powertrain code
reader. Disconnecting the battery may not work as the BCM should keep
collision data stored in the event of power failure.
Why go through all the trouble of clearing them without checking the codes.
Pull the codes, find out why the light is on. The OP said he replaced the
airbags, however, you have to replace the airbags, the sensing and
diagnostic module and/or the impact sensors in the collision area after a
collision, NOT just the airbags.