• On Windows, if Firefox is installed to "C:\path\to\Mozilla Firefox", FIREFOX_NEW will be "C:\path\to\Mozilla Firefox\updated". :Robert Strong 02:16, 18 October 2011 (PDT) I suspect the rename operation will be faster if the old is renamed to FIREFOX_OLD, the new is renamed to FIREFOX_NEW, and FIREFOX_OLD is then deleted while Firefox is starting.
On Mac, we basically move the Contents directory in the FIREFOX_NEW directory over to the Contents directory in the existing installation, remove the now empty FIREFOX_NEW directory, write "succeeded" to the manifest file, and restart Firefox. :Robert Strong 02:19, 18 October 2011 (PDT) There is also the precomplete file in the root of the bundle.