// Create base class criterion to avoid setting keyword specific fields.
Criterion criterion = new Criterion();
criterion.setId(criterionId);
// Create ad group criterion.
AdGroupCriterion adGroupCriterion = new AdGroupCriterion();
adGroupCriterion.setAdGroupId(adGroupId);
adGroupCriterion.setCriterion(criterion);
// Create operations.
AdGroupCriterionOperation operation = new AdGroupCriterionOperation();
operation.setOperand(adGroupCriterion);
operation.setOperator(Operator.REMOVE);