how to update unique field for multiple entries in django

I have a simple Django model similar to this:

class TestModel(models.Model):
    test_field = LowerCaseCharField(max_length=20, null=False,
                                verbose_name='Test Field')
    other_test_field = LowerCaseCharField(max_length=20, null=False, unique=True,
                                verbose_name='Other Test Field')

Notice that other_test_field is a unique field. Now I also have some data stored that looks like this:

[
    {
        test_field: "object1",
        other_test_field: "test1"
    },
    {
        test_field: "object2",
        other_test_field: "test2"
    }
]

All I'm trying to do now is switch the other_test_field fields in these two objects, so that the first object has "test2" and the second object has "test1" for other_test_field. How do I accomplish that while preserving the uniqueness? Ultimately I'm trying to update data in bulk, not just swapping two fields.

Anything that updates data in serial is going to hit an IntegrityError due to unique constraint violation, and I don't know a good way to remove the unique constraint temporarily, for this one operation, before adding it back. Any suggestions?