How to install chrome extensions/plugins/add-ons from unofficial sites?

By default google-chrome browser allows to install the extensions that are got from google's chrome webstore only.  So, what if you not find a useful extension in chrome's web store but available/downloadable with some third party website...?   How to install those extensions(.crx files)?

* Basically the google-chrome's extensions are .crx files.
* The extensions that available with chrome webstore be installed directly
* To install these third party extensions do the following.

1. Open your chrome browser -> Click on the  symbol(at the right top, just below the close,minimize buttons of the browser window) -> Tools -> "Extensions"
2. Now open the directory where you have your third party chrome extensions(.crx files), then drag and drop the .crx file into the chrome browser tab where the "Extensions" is open.
3. Now google-chrome browser will prompt you with "cancel" & "add" button.  Click on the "add" button the extension will be added to the browser.

How to install extensions of google chrome? / "Add to chrome" button missing/not shown.

First is first..
1.  Why i write this blog post.
  Previously i have google chrome browser (version details are in the following image)

google-chrome old version

When i try to install the chrome extensions in this browser.. i can search, view, read about the extension, can see the review and so.. but the problem is there is no "Add to chrome" button anywhere in the extension detail.. :(

I spent 10 minutes to find the solution but.. no fruitful information is found.  So, atlast i reinstalled my google chrome browser with the newer version(details in the following image).  Now when i browse for the extensions, it shows "Add to chrome" button also.  So, i can easily install the extensions now.

google-chrome new version

2.  How to steps
2.1 Go to the google chorme extensions website
* Click on the wrench -> Tools -> Extensions -> Get more extensions (or)
* Directly going to the chrome's webstore.
* Open new tab, at bottom you can see a label named "Apps" click on that, then click on chrome web store
2.2 Browse the extension in the "search the store" text field and finalize which extension you want
2.3 Click on the extension, there you can see a "Add to chrome" button, just click on it.. Your extension is installed.

Link to the Dictionary extension.