I have a document with chunks of XML data, but in-between each chunk there's plain text. How do I extract just the XML data?

ie

```
blah blah blah
===: text text text :===
 <?xml version="1.0" ?> 
    <Data>
       <Line>information</Line>
       <Line2>more information</Line2>
    </Data>
===: text text text :===
blah blah blah
blah blah blah
===: text text text :===
  <?xml version="1.0" ?> 
     <Data>
        <Line>2nd information</Line>
        <Line2>more information</Line2>
     </Data>
 ===: text text text :===
 blah blah blah

```

the text withing the ===: :=== will always be different but do not need to be included.