Customizing Wufoo Form: How to hide a label

I'm almost done customizing my wufoo form but I still need to hide the radio elements' labels. How do I do this?

I've gone from this:

To this:

But, as you can see, I am unable to hide the original text of the radio button. The following is what I've tried but this approach hides the radio button as well. I just want to hide the text.

/* :not(#foo) > is a rule filter to block browsers that don't support that selector from applying rules they shouldn't */

li:not(#foo) > fieldset > div > span > input[type='radio'] + label {
  display: none;
}

Here is the html:

<li>
  <fieldset>
    <div>
        <input id="radioDefault_2" name="Field2" type="hidden" value="">
        <span>
            <input checked="checked" class="field radio" id="Field2_0" name="Field2" onchange="handleInput(this);" onmouseup="handleInput(this);" required="" tabindex="1" type="radio" value="Very valuable">
            <label class="choice" for="Field2_0">Very valuable</label>
        </span>
        <span>
            <input class="field radio" id="Field2_1" name="Field2" onchange="handleInput(this);" onmouseup="handleInput(this);" required="" tabindex="2" type="radio" value="Somewhat valuable"> 
            <label class="choice" for="Field2_1">Somewhat valuable</label>
        </span>
        <span>
            <input class="field radio" id="Field2_2" name="Field2" onchange="handleInput(this);" onmouseup="handleInput(this);" required="" tabindex="3" type="radio" value="Not valuable for us"> 
            <label class="choice" for="Field2_2">Not valuable for us</label>
        </span>
    </div>
  </fieldset>
</li>