cant get hd to mount

[Brian McKay]

osx no longer recognises my docs hd, i read about the fix an have tried 
instructions for the osx fix, (linux shows blank screen, due to video 
issues) but some of the commands wont work
For ex:
Last login: Thu May 29 16:19:20 on ttyp1
Welcome to Darwin!
[Brian-McKays-Computer:~] brianmckay% gunzip pdisk_OSX.gz
[Brian-McKays-Computer:~] brianmckay% sudo ./pdisk_OSX
Password:
sudo: ./pdisk_OSX: command not found
[Brian-McKays-Computer:~] brianmckay%
help