Well, assuming you can get the engine and tranny to fit with an Accord front suspension (CL-S has the HLSD, and a different suspension geometry), you must purchase a CL-S ECM, the entire exhaust from the headders back, not to mention adding for the cut and pasting for the peddals, and gear shift (CL-S has it's own shift linkage, not shared with any other Honda). If he want's to shell out the cash, I'd say a rough estimate of about 15,000 when it's all said and done. Unless he wants to try to do it himself, which I do not recomend. Sheesh. That's a down payment on the real CL-S which is faster, handles better, looks better, and is more luxurious than his Accord.