The party requesting recusal has the burden to produce evidence establishing bias, prejudice or unfairness.
The party requesting recusal must show that the bias, prejudice or unfairness raises a substantial doubt as to the jurist's ability to preside impartially.
Generally, a motion for recusal is directed to the jurist who is being challenged. The jurist then makes a determination of his or her ability to proceed impartially. This is a personal decision and unreviewable absent an abuse of discretion.
It can be an uphill battle to get a Judge recused. You will need strong evidence which shows that the Judge's continued involvement in the case would cast doubt on the integrity of the judiciary.