Rated 5 out of 5 stars

by Bru on Nov. 13, 2012 · permalink

To use with the latest version of Thunderbird, simply modify the .rdf file contained within the .xpi file with a text editor like Aquamacs (free from http://aquamacs.org/). Replace the version number in the Thunderbird section of the .rdf file with the current version. Save the modified .xpi file and install. I used to be able to modify the .xpi files by opening them up in WinZip and editing them when I was using a Windows machine. The right text editor is crucial.