Replacing an Old Label with a New Label
Brikit Targeted Search 2.0+ makes it easy to swap one label for another.
Use the "Replace any label" tool in the Folksonomy interface to replace one label with another. Doing so replaces the old label with the new label on all the pages, blogs, and attachments in which you have edit permissions.
Check if you have Targeted Search 2.0+ installed
This "Replace any label" tool is only available in Targeted Search versions 2.0 and greater.