XML document add data xsi:type xsd:string attribute

I have a code to return an xml document, however a wanted it to be of this output :

But what i actually get using my program is this

Ex: <user_id xsi:type="xsd:string">12345678</user_id>

became : <user_id xmlns:p3="http://ift.tt/ra1lAU" p3:type="xsd:string">12345678</user_id>

Here is my code for extracting the XML document :

Thanks!