From the Guardian:
A woman applied to the Leo Baeck (Rabbinic) College. The admissions committee decided that although the theological arguments were still raging, there could be no objection to her acquiring Jewish learning and let her in.
Five years later they realised that as she had finished the course and satisfied all requirements, they had no reason not to ordain her and in 1975 Britain had its first female rabbi.
However, there was another hurdle to overcome: the congregations. When the early female ministers came to preach, there were threats of splits and predictions of walk-outs. In the event, almost none of these occurred.
Today, around a third of congregational rabbis in Reform and Liberal Synagogues are female (though still none in the Orthodox). It is not that they have ousted male colleagues, but that they have plugged the gap that was already occurring as male applicants declined.