How to Install latest addon

You can download latest addon from here. https://github.com/Ericsson/exchangecalendar/archive/master.zip

1. "You will be downloading file exchangecalendar-master.zip"

2. "Unzip the file"

3. "In exchangecalendar-master folder"

4. "select all the items,compress them as zip"

5. "Rename the compressed .zip file to .xpi"

6. "Then it is xpi add-on which can be installed"