Firefox Hack: How To Modify Old Add-Ons

During the last Firefox update, from 1.5 to 2.0, some of your favorite extensions add-ons may not have been update. If thats happened to you, you are in the right place. Just follow the simple instructions below and you will be able to run your Firefox extension no matter what version the extension's home page says it is compatible with.

First step; get yourself an extension. I found that a great extension called Copy URL has not been updated for Firefox 2.0 as of yet. So go to that page, right-click on the "Install Now" button and do a "save as" to your desk top. Go to your desktop and rename the copy_url-1.0-fx.xpi to copy_url-1.0-fx.zip. If you cannot see the .xpi in the file name, open up My Computer -> Tools pull-down menu -> Folder Option. Go into the View tab and un-check "Hide extensions for known file types", then do the rename on your desktop.

[The rest of the instructions after the jump]

Once you have the file renamed, open the zip file with your choice of zip programs. Just open it, don't extract anything. Click and drag the "install.rdf" file to your desktop and open it with Note Pad or something similar. Once you have that open, you will notice, about half way down the page, something that says 1.5.0.4. This part of the extension tells Firefox what version of Firefox the extension is compatible with. Just go ahead and make that 1.5.0.4 into a 2.0.*, like this: 2.0.*. Save and close then drag that file back into the zip window you have open. Go ahead and close down the zip program that you have open and rename the .zip part of the file name back to .xpi. Then just double click the extension and Firefox will take it from there.

And you have now successfully modified an add-on that was only compatible for up to Firefox version 1.5.0.4 and made it work for the latest and greatest version of Firefox. Congratulations! Feel free to now look into any other Firefox add-on. If Firefox says that the version of the add-om is not compatible with your version of Firefox, just do the above and you're all set. This also works the opposite way, as well. Feel free to replace the max or min version number with what ever version of Firefox you have. Just be warned, some add-ons may not be meant for the version you have. A lot has changed between version 1.5 and 2.0 and the buttons may not match up any more. These instructions can also be applied to any other Mozilla product that accepts add-ons.