Cherokee Jeep Grand CD Changers - 10-Disc "high octane cause engine light" Questions

high. does anyone know how to change from radio to cd stacker on a Philips ministero p.t. N / 61 / 01208 / 22837 / A D.M. 25/6/1985 / 27/8/1987 90 RC 348 / 53 made is singapore 5V009632 90903134853900