PLEASE! does anyone know how to reset the engine management light on the dash?. Just fitted a new coil pack to my beloved 9n, and this light is staying on. S

ame thing happened a couple of years ago , but then i took it into a garage after, and they reset it by plugging a diagnostics computer under the drivers side foot well. This cost 40 quid!!! ( 2 seconds work).I was just wondering if there was a manual procedure???.
Thanks
Vaughan