You need Microsoft Internet Explorer and Blackberry Desktop Manager installed in your PC (Blackberry called it "Desktop").
Open your Blackberry Desktop Manager, and let your Blackberry device connected with your PC, insert the security lock code on the PC and device. Then they will be connecting by itself.
Next, open Microsoft Internet Explorer, and go to http://na.blackberry.com/eng/devices/features/social/facebook.jsp
to go to Facebook Installation on Blackberry Official Site.
Follow the instruction until you see a download button which let you to download Facebook Application through your PC. Click it, a prompt will appear and ask you to turn on an Active-X control. Allow Blackberry Homepage to do 'something' in your PC by allow it.
And then wait until the site asked you the security lock code. Then submit it.
Wait until the PC and device finish its progress. But in the middle of the progress, a window will appear and ask you to allow or deny some application data, allow them to continue the progress.
Wait until it sucessfuly load and instal the application to your Blackberry device.
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