Open a shell, cd into the directory containing the tarball (the file ending .tar.gz, I'll call it printerdriver.tar.gz from now on, you substitute whatever the name of the file actually is), and type the following at the command prompt:
Code:
tar zxvf printerdriver.tar.gz
This will unzip (z) and untar (x) the file (f) whilst telling you what it is doing (v), this should create a directory probably called printerdriver, look in here for either a README, or an INSTALL file, read them and follow the instructions contained within.
Cheers
Amos