Answer

I think that from a halakhic standpoint there is no possibility. Strictly speaking, a Torah law is overridden when the circumstances require it through passive omission, not through direct action. And even that can apparently be done only by the Great Court, the supreme religious court (otherwise there is no source of binding authority against the commandment that the Torah obligates us to observe).
However, it already appears in several places in the medieval authorities (Rishonim) that the sages sometimes overrode even through direct action. In this matter there are no fixed rules, and it has to be a decision of the sages of the generation according to the intensity of the need and the severity of the prohibition.