[TUT] Installing "incompatible add ons" with firefox

Lets say you're running 3.1 beta Firefox and the add on compatibility is only for 3.0.0, it wont let you install because it's "incompatible".

Things you will need:
7-Zip(Winrar will work also)
Firefox User Agent Switcher(or an alternative browser)


Steps:
1. Switch user agents(Tools>User Agent Switcher) or open an alternative browser
2. Go to the addon firefox page and right-click save as on the download button
3. Open the archive with 7-Zip or Winrar
4. Open the install.rdf file
5. Edit where it says <em:maxVersion>3.0.*</em:maxVersion> and change the version inside to your version of firefox(To get your firefox version go to Help>About Mozilla Firefox) and save it
6. Open the XPI file with firefox and you're done


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