Rename extensions in subfolders

[PunchCardBoy]

OK, I have searched for the answer but haven't found anything close enough for me to understand exactly what to do.

OK, so in the tree view I have chosen the folder topFolder. It has subfolders that in turn have subfolders too.

So in the list view I can see the first level of subfolders and the files in topFolder.

Now what I want to do is this:

Rename every file in topFolder and its subfolders that have the extension .flv to .flx but leave all other files untouched. And not change any folder names.

Any suggestions?

[ack-hh]

Under "Selections (12)" uncheck "Folders" and check "Subfolders"
In the list view select all files with the .flv extension
Enter "flx" (w/o quotes) under "Extension (11)" (mode will switch from "Same" to "Fixed")

[PunchCardBoy]

Thank you for the reply.

I had to download another renaming software to do this but I will have a look at your solution and see if I will get a better understanding, not only for this specific problem but also for how to apply arguments in general.