Remember the Federal Government does not have any money to pay. What they do is collect money from one group, take their cut, then pass what is left to another group.

So the descendents of slave owners would pay the descendents of slaves.

One little quirk with this is that there will be many who when they go to collect their money will find out that they are the descendent of one of the thousands of BLACK slave owners and will have to PAY the reparations.