findind and replacement of value in xml

findind and replacement of value in xml

I have a query that is i have different xml which contain these below tags
<property name="abcaddress">
<value>Rt:try:yutt</value>
Now I am at the root of the project that is at /opt/app/pro1 now in side
pro1 there may be many directories which may contain different xml's in
side in some xml's there may be this tag so i need to search and replace
the tag with TEST1 , so finally after replacement it would look like ...
<property name="abcaddress">
<value>TEST</value>
please advise what will be the appropriate unix command to achieve this..!!