How to make out-datedextensions available again in Firefox

Firefox is updating everyday with nightlies,if you are interesting in using the latest version as me..
Here is a method that will help you to keep your extensions available.
1)Download the extension .xpi file [It's obvious that you should have a certain extension at hands]
2) Open the unrecognized .xpi file with WinRAR. Why WinRAR? Because the xpi file is actually in zip format~~
3)Find the install.rdf file
4)Open it with an editor for example EmEditor or Notepad in Windows.
5)Find the line
<em:targetApplication>
            <Description>
                <em:id>{ec8030f7-c20a-464f-9b0e-13a3a9e97384}</em:id>
                <em:minVersion>0.7</em:minVersion>
                <em:maxVersion>1.0+</em:maxVersion>
            </Description>
        </em:targetApplication>
And now change the line <em:maxVersion>1.0+</em:maxVersion> and change 1.0+ to a larger version for example the version you are using.

Basically  it will  make most of the unrecognized extensions available again