Preparing your system
Remove your existing Flash plugin, if you have one installed. This command will remove Flash 9 if you installed it from Ubuntu’s repository
sudo apt-get remove flashplugin-nonfree
For 32 bit Users
Install adobe Flash Player 10 in Ubuntu 8.04
First you need to download the .deb package from here
Click the download link to begin installation. If a dialog box appears, follow the instructions to save the installer to your desktop.
Save the .deb package to your desktop, and wait for it to download completely.
Double-click on the .deb package and follow the instructions to complete installation.
Use the following command from your terminal
sudo dpkg -i install_flash_player_10_linux.deb
This will complete the installation.
First you need to make sure you have installed apturl using the following command
sudo apt-get install apturl
Now you need to go to the download page menctioned above click on linux section from dropdown box select APT for Ubuntu 8.04+ Click the download link and follow the instructions to complete installation.
To get the most up-to-date Flash Player in the future, issue the following commands from the Terminal:
sudo apt-get update
sudo apt-get install adobe-flashplugin
Verify your plugin Installation
To verify the plugin is installed in Mozilla, launch Mozilla and choose Help > About Plug-ins from the browser menu.
In your broweser enter the following command and check
For 64 bit Users
Thanks to Alejandro for this nice script.First you need to Download shell script from here
Using the following command
Now you need to give execute permissions using the following command
sudo chmod +x flash10_en.sh
Run the script now
sudo sh ./flash10_en.sh