Tricky question..
If I am able to alter human traits, etc, i'd adjust it so that emotional triggers/responses would be less, and people would be more logical. Next, in terms of communication, i'd remove the need to sugar coat.
If I am not able to alter human traits, and instead have humans do what i tell them to do with their existing traits, then honestly it will turn into a dictatorship for a generation or two.
I'd pour in resources from first world to third world countries to bring them up to a certain standard, it wont be equal, because humans being humans they would still have their individual traits but the gap would lessen.
i'd take the existing geographical borders and lock them down for 5-10 years.
The Americas (North and South) would be forced to trade within their border only for that time, same with Europe and Asia.
I'll lift the ban after 5 years and allow for cross country travel.
Within each country/continent, i'd transfer wealth. Those who own farms but dont actually have anyone in their family doing the farming will have the farms removed and transferred over to the actual farmers and so on.
I'd have to revamp the school system as well. Trade-skills will be mandatory. Men will be taught how to use a sewing machine, women will be taught how to change a tire. I wouldn't care what their individual preferences are, i'd only care that the skills were taught and they have a reasonable grasp on it.
Psychology and Environmental Sciences would receive priority, and i'd crack down hard on things whose value is feelings based, ie: the price is determined by whatever the person is willing to pay for it.
Alternatively, i am leaning towards @HouseofMortok 's idea.