for future reference, if you have the kernals that support clockwork mod recovery, eg. CF-ROOT, Voodoo etc,
1) You place the cwm zip file on the sd card.
2) Switch phone OFF
3) Hold Volume UP + Home and the Power key until the Samsung galaxy writing appears.
4) You will now see a menu, in the list will be the option to "install zip from sd card" use the power button as select key and the vol. keys to move up and down.
5) After clicking install zip from sd card, find the zip file you want to install and select it, it will then ask you to confirm.
6) After file installed click go back, and then reboot phone. DONE
Wrote in the simplest way I could, hope it helps