To install this add-on to your browser follow below steps :
1. Go to the download link bellow OR click here
2. Now you will see Add To Firefox button click it.
3. Wait few seconds so that till the downloading process finish.
5.Wait a few seconds and you will asked for restarting your computer.Click Restart Now and done your add-on successfully install in your pc.
Click Here To Download ChatZilla Add-on