Caste by definition is about treating people as unequals. And thus is wrong. Human equality is the goal. And so religion has to be challenged. The social order has to be challenged. '
The best way to challenge caste is by converting. I think Dalits should convert en masse into Buddhism, Christianity or whatever religion of choice. And in the process they should give up their Hindu first and last names. In the Hindu order it is your last name that gives away your caste. And so in converting you have to get rid of your last name.
Another way is intermarriage. But the caste system is not designed for that. It does not make room for intercaste marriage, although it happens. There is no way to say you do not belong to any caste, you are just plain Hindu. To be Hindu is to be a member of this or that caste.
There can be an urban flavor where you have watered down caste to just celebrating the major festivals.
Urbanization, education, modernization, and wealth creation are other ways to fight casteism.
But the best way is conversion. Ambedkar felt the same way. I agree with him.