Firstly, races are ranked. White is the best, black is the worst. Yellows and Browns are in the middle. In order to achieve equality among humans, their knowledge, shape, body etc must be equalised.
In this utopia, whites and yellows are approximately equals, but the negro exhibits a shape such that, "iron faced, big teeth", "stature like a bull", "chest is hairy", "hands and feet are black", "as stupid as cattle", "looks intimidating".

(holy shit) It will be a difficult task to improve this race, however it must be done if human equality is to be achieved.
Secondly, to achieve this utopia of equality, the races must be equalised. Race must be eliminated from the equation. The best method is race mixing through generations.
The author's appraoch is "Yellows and whites mix with blacks and browns, yellows and whites mix with each other". He believes this will improve the human race. Yellows mixing with whites will make them white, yellows mixing with browns and blacks will eliminate the brown and black genes. Eventually, there will be no browns and blacks. "Billions of yellow and white superior genes mixing with one or two inferior bastardised browns or blacks will lead to the bastard genes of browns and blacks diminishing, thereby allowing the billions of superior races replacing and improving them".

Jesus...
It gets even better...
"Brown and black are considered inferior bastards, who would want to voluntarily racemix with them?", the author attempts to solve this riddle with a system "which benefits individuals who voluntarily racemixed with brown and blacks". Such that "if a man [of the master race] willingly breeds with brown or black women or if a woman [of the master race] willingly breeds with brown or black men, they both should be rewarded greatly" under the pretence of "substantiating to the project of human improvement".