We can start with cognitive behaviour therapy and nicotine replacement therapy. Kindly share his general condition like does he suffer from any other medical illness , does he understand the seriousness of the condition, does he himself ready for qutting.
It will be difficult but with a firm attitude he can do it
Next Steps
For further clarification, complete evaluation, correct diagnosis and treatment and prescription feel free to consult me on this PRACTO APP. Stay safe and take care of yourself