Xml problem remove node

Hi i am trying to create a sort of xml proxy..
Receving xml through rest and then using nokogiriand mechanize posting
it to another
api. This last api isnt accepting true xml as i will explain.

The api needs
<hash>
  <item>
    <bid>1</bid>
  </item>
  <item>
    <bid>2</bid>
  </item>
</hash>

I am using rails4 with the activeresource gem installed..
The problem is i am getting an node type array that is unwnted..

<hash>
  <item type="array">
    <item>
      <bid>1</bid>
    </item>
    <item>
      <bid>2</bid>
    </item>
  </item>
</hash>

What i actually need is

<inventory
  <item>
    <bid>1</bid>
  </item>
  <item>
    <bid>2</bid>
  </item>
</inventory>

I was able to get the root node from has to inventory i just now need to
get rid of the item type array..