I need to update my xml with a tag in every element

[rashid4844]

I have a xml like this:

<LangPref>ENGLISH</LangPref>
<POI>
  <POINum>1024211680</POINum>
<POI>

I just need to add namespace like below

<ns1:LangPref>ENGLISH</ns1:LangPref>
<ns1:POI>
  <ns1:POINum>1024211680</ns1:POINum>
</ns1:POI>

Any suggestion on the best way to do it?