[Discuss] More root problems

[SJF]

Sorry to be so dense about this but I'm trying to set up Firefox in
Ubuntu 8.04 and a webpage informs me that the I cannot run a 'flash'
item without the Flashplayer. 
I dutifully download 'install_flash_player_9_linux.tar.gz', and unpack
it:flashplayer-installer (which is locked) and libflash.so.
So the question is how do I get from here to get it installed in
Firefox? It won't install without root authorization and I don't know
what application to sudo in a terminal window to finish the installation
(or am I on the wrong track entirely).
Stan Fisher