Replace ACF checkbox fields from frontend?

I’ve a type that has a checkbox made via ACF,

        <?php $newfield = get_field_object('field_614b59da0b09b');
        $newclasses = $newfield['choices']; 

        foreach( $newclasses as $worth ): ?>
            <enter sort="checkbox" identify="<?php echo $value; ?>">
            <label for="<?php echo $value; ?>"><?php echo $worth; ?></label>
        <?php endforeach; ?>

Normally you can replace easy enter fields with update_field('instructor', $_POST['teacher'], $postID); however how do you deal with the checkboxes?
Thanks.