How to install the firefox 4 beta on linux?

Please follow these steps to install firefox 4 beta or any version of firefox.

Step-1: Download you firefox copy from http://www.mozilla.org

Step-2: Now open your terminal and copy firefox-*.tar.bz2 from your download folder to /usr/src/, you must be a root to copy firefox in /usr/src folder.
# cp firefox-*.tar.bz2 /usr/src/

Step-3: Extract firefox using tar command
# tar xjf firefox-*.tar.bz2

Step-4: Now remove old firefox link and create a new link to replace the old firefox version
# mv /usr/bin/firefox /usr/bin/firefox-old
# ln -s /usr/src/firefox-*/firefox /usr/bin/firefox

you can access your old firefox version any time, open terminal and type the following command
$ /usr/bin/firefox-old

Step-5: You can launch firefox browser by using command firefox

# firefox

Step-6: Now create a desktop luncher, right click on desktop and select create luncher. It will open a "Create Luncher" dialog box, fill the following information and hit ok.
Type: Application
Name: firefox
Command: firefox

Thats it, Enjoy :)