You are a mechanics how to reset set management light without a computer resetter?

Are you referring to the Check Engine Light? If so, you can try disconnecting the positive battery cable for 30 minutes. This will reset the light on pre-OBD2 vehicles and some early OBD2 vehicles. If that does not work then the only way is to use an OBD2 scan tool. Of course if you do not repair the problem that caused the light to come on in the first place, it will just come back on again.