That's a tough one. Contra the blather from Seoul, he can't just wave a magic wand and turn North Korea into China or Vietnam. It simply isn't that easy.
Conditions are different, and the mess is far worse.
Sure, he should decollectivize. No simple salvation there. That's easier, in principle. The government tolerates this, but that's all. If Kim Jong-il learned anything in China, he should swiftly do a Deng Xiaoping and say loudly and clearly that markets and private enterprise are A Good Thing, to be actively encouraged.