XML changing values in elements

Question

I have some XML data that looks like, I am trying to modify the X Y and CX and CY values across about 20 different XML's to be exactly double the current value.

<Label item="ADLW_PLLLbl">
<ScreenID>ADLW_PLLLbl</ScreenID>
<Location>
  <X>5</X>
  <Y>5</Y>
</Location>
<Size>
  <CX>105</CX>
  <CY>24</CY>
</Size>
<Text>Personal Loot</Text>
<TextColor>
  <R>255</R>
  <G>255</G>
  <B>255</B>
</TextColor>