Remove XML attribute

Using an XML document in powershell how can you remove an attribute string from an element? Not looking for a solution that uses Get-Content, but one that uses:

    $xml = New-Object XML

    $xml.Load("$pathToFile")

How can I use the XML DOM to remove the attribute?

In the example XML below, lets say that I want to remove the lang attribute from the title node for all entries. Note that the value of lang can be different as in the example below, thus <title lang="en-US"> and <title lang="en-GB"> would both become <title>

Example XML:

<?xmlversion="1.0"encoding="UTF-8"?>
<bookstore>
  <bookcategory="cooking">
    <titlelang="en-US">Everyday Italian</title>
    <author>Giada De Laurentiis</author>
    <year>2005</year>
    <price>30.00</price>
  </book>
  <bookcategory="children">
    <titlelang="en-GB">Harry Potter</title>
    <author>J K. Rowling</author>
    <year>2005</year>
    <price>29.99</price>
  </book>
</bookstore>