Your boyfriend needs to stop speaking ill of the woman he chose to make babies with if those are in fact his words...
Secondly, he cannot remove her name from the birth certificate because she is still biologically their mother and without a mother, those children would cease to exist. Also, tell him that a responsible father would have ALREADY had birth certificates and social security cards for his children so he shouldn't throw stones. Nothing stopped him from getting them since the day they were born.

