By the transvaluation of values Nietzsche meant a complete reappraisal and reconfiguration of a society's values and moral commitments. Every value is to scrutinized and overturned. The transvaluation of values is demolition work, a clearing of the ground, so that a new value system could replace the old.
In the hands of Nietzsche, the transvaluation of values is radical work. In the transvaluation of values "good" would become "bad" and "bad" would become "good." Light and darkness were to switch places.
What sort of demolition work was Nietzsche intending?
If you're familiar with Nietzsche, you know his target was Christianity. The values Nietzsche wanted to reevaluate and uproot were Christian values. As a student of antiquity, Nietzsche felt that the old pagan values of the Greeks needed a revival. Nietzsche wanted virtues of power, strength, victory, nobility and dominance to return to Western civilization. These values would be embodied by the rise of the Ćbermensch-- the "super-man" or "over-man."
According to Nietzsche, this retrieval of pagan virtues was necessary because Western civilization had fallen into decadence and decay due to what Nietzsche called the "slave morality" of Christianity. Instead of valuing and praising the glorious achievements of the "super-men" among us, Christianity preached pity and meekness. Christianity was for the Betas in society, not the Alphas. The limp and passive Christian values were, declared Nietzsche, "anti-life."
According to Nietzsche, the world needed a return to "top-down" virtues, such as power and dominance, where the strong would be returned to their rightful places of rule and authority over the herd of humanity. The "bottom-up" virtues of Christianity, concern and pity for the "least of these," needed to be uprooted. The Christian commitment to equality was to be replaced by hierarchy. As Nietzsche wrote, the rise of the "super-men" would involve "the elimination of equality."
In summary, the Christian call to love was to be replaced with a "will to power," a drive for expansion and conquest. As Nietzsche described the "will to power": “life itself is
essentially a process of appropriating, injuring, overpowering the alien and the weaker,
oppressing, being harsh, imposing your own form, incorporating, and at least, the very
least, exploiting."
Given all this, it's not surprising that Nietzsche would describe his "transvaluation of values" as being "anti-christ."
And yet, in the annals of Western history, Nietzsche wasn't the first to attempt a "transvaluation of values." That Nietzsche wanted a return to pagan values was evidence that a prior revolution had occurred, the transvaluation of values that Nietzsche wanted to overturn and reverse.
This was the moral revolution of St. Paul.