Here is the video guide:

Links:
–XDA thread
–Official CWM site

Written guide
By XDA member mskip

How to Install ClockworkMod Touch:
1. Download the attached tar file at the bottom of this post. DO NOT EXTRACT THIS FILE! If you end up with a recovery.img file then smack yourself and start again.
2. Download Odin (windows only) at the bottom if you don’t already have it and unzip it to a folder on your PC
3. Reboot into Download Mode: Power off your device, Hold down the ‘HOME’ + ‘VOLUME DOWN’ buttons and press the ‘POWER’ button for about 2 seconds until a WARNING! Screen appears. Press the ‘VOLUME UP’ button to enter Download Mode.
4. Plug your usb cable in
5. Start Odin (double click Odin3_v3.04.exe).
NOTE: When Odin opens you should see that the first box at the top under ID:COM should turn blue and ‘Added’ should appear in the message box in Odin.
6. Make sure ‘Auto Reboot’ and ‘F.Reset Time’ are ticked in Odin and nothing else.
7. Click on the ‘PDA’ button in Odin and browse to the recovery-clockwork-touch-5.8.4.3-i9300.tar file that you downloaded.
8. Click on ‘Start’ to flash CWM to your phone.
NOTE: You can see whats happening in the message box in Odin. When the flash completes you should see ‘PASS’ in the top left the box will turn green and your phone will reboot.
9. You now have CWM Touch Recovery permanently flashed

How to Access ClockworkMod Touch
1. Unplug the USB cable.
2. Shut down the phone.
3. Hold down the ‘HOME’ + ‘VOLUME UP’ buttons and press the ‘POWER’ button for about 5 seconds to enter Recovery Mode.

Hope this helped you!
–TotallydubbedHD