Replace different texts

Hi , i want to edit an xml file
for example:
[TEXT1]
<PageId>Circuit</PageId>
<ids>
<index>0</index>
<id>2613452513</id>
</ids>
<ids>
<index>1</index>
<id>125509666</id>
</ids>
<ids>
<index>2</index>
<id>3930022360</id>
</ids>
<ids>
<index>3</index>
<id>957701799</id>
</ids>
Copy from text1 to text 2
<index>3</index>
<id>957701799</id>
then when i edit (in text2) save in text1
Thanks :)