Renaming multiple folders

Hello,

I've been trying to write a script to rename multiple folders in a directory but am not having much luck! The problem I have is that the path of the folders that I need to rename will change, for example:-

C:\TEST\FolderA

C:\TEST2\FolderA

I need to rename FolderA to Folder B but cannot work out how to do it. Any help you guys can offer would, as always, be most appreciated.

Andrew