The procedure's relatively simple. We construct a series of "correct" memories on the computer and play it back to his prepared, unconscious mind. Through pure repetition, the mind is forced to absorb what we feed into it. It's like telling someone every time you meet him how wonderful it was to see him again, even if you've never met him before that. After some time, he'll believe that he must have been mistaken and did indeed know you. The human mind is so very malleable.
Ludovico would have been proud.