I want to replace the value in an attribute in a XML. This attribute comes multiple times in the xml. How can i replace these all at once

my xml lools some what like below :

```
 <Example>
  <A>
   <B Type = "x">qqq</B>
   <B Type = "x">www</B>
  </A>
  <C>
   <D Type = "x">aaa</D>
   <D Type = "x">uuu</D>
  </C>
 </Example>

```

I want to replace all x with y