I don't have a specific quote on the cost, but to have it done by a shop would astronomical. To do it yourself, you would have to source a manual gearbox, clutch, pedals, all mechanical connections, most likely intermediate shafts to the wheels, the ECU from a manual car, and TCU, and a complete engine wiring harness from a manual because there are several sensors that are integrated. I am sure that you have heard it from many others, but a 2001 Accord is still worth enough that you should be able to sell it and buy a manual version for far less money and much quicker if you still need to drive the car. But, I understand that it's not always about money, but about the challange and the fun. So, good luck, all things are possible.