How do you reset the check engine light on a 93 Mazda mpv?

On my 94 MPV the Mitchell on demand repair manual says to remove the panel in the dash where your display is, their is a small screw, take screw out of the place it is and put it in the other place provided. I haven't done this yet but my light stays on also, they come on automatically at 80,000 miles. Hope that helps. Disconnecting the battery won't reset it.

A friend of mine told me to disconnect the battery. Not 100% sure, just what i was told.