u can use the following way..this is part of suggestion and you can carry it from next sequence onward
find / -type f -name <pattern of file> -exec sed 's/search text/replaced text/g' {} \;
this will search the particular
pattern of files from root, then search the
<search text>and replace the same with
<replaced text>
then loop the above one and rename the same .
best of luck..