HOW-TO: Modify an extension to install under Firefox 2.0

The following steps have been tested on the del.icio.us Firefox extension. I read in this post by David Findlay that the extension seemed to work fine in Firefox 2.0 despite it's maxversion property. I attempted to follow the steps therein, but was too impatient and failed to wait for the second restart before giving up and uninstalling. Due to my massive del.icio.us addiction, however, I had to invest a bit more effort. Creating XPI Installer Modules on the Mozilla Developers Center was extremely helpful, and a little guesswork led to the following procedure. Step 1: Download the XPI file by right-clicking on the link (usually a big button that says something like "Install Now") and selecting "Save Link As..." Step 2: XPI files are (conveniently) nothing more than specifically ordered ZIP files it turns out, so you can open them with just about any compression utility. I use IZArc out of habit and because it's free, but most any would do. You might even be able to do it from Windows without any special software if you want to badly enough. Whatever your preference is, right click on the XPI in explorer and use "Open With..." to view the contents of the file. Step 3: In the root directory will be a file named install.rdf. If your compression utility allows you to edit files in-place within the XPI, open it up from there. Otherwise, extract the file and open it with any text editor. I'm a big fan of EditPad Lite because (again) it's free and knows how to deal with *nix carriage returns, but even notepad.exe will do fine for this. Step 4: Find the line that says something like 1.5.0.* or and change the value to "2.0.*". Step 5: If you had to extract the file to edit it, go back into the archive and delete install.rdf, then add your modified file. If you made your changes in-place, you can just save the file. Step 6: If there is a folder labeled META-INF in the XPI, delete it. This contains the signature information for the extension, but it will no longer match since you made changes. However, it doesn't seem like much of a stretch to trust this particular unsigned XPI, since you just unsigned it. Step 7: Do whatever you need to do to make sure changes to the XPI are saved, then close your compression utility. Step 8: Right click on the XPI file, select "Open With...", then choose Firefox from the list. Click the Install button, Restart Firefox, and you're good to go. Hope this works for everyone, it seems like a fairly easy procedure. Of course, you should keep in mind that some extensions are marked incompatible for a reason. Don't do this at all if you're not comfortable crashing Firefox completely, potentially losing all of your settings, probably suffering premature balness and possibly going to hell.