Please see the tutorials forum [Only registered and activated users can see links Click here to register]
If you are rooted, see Ranpha and Yulipis methods.
If you are not yet rooted, see the rooting tools forum [Only registered and activated users can see links Click here to register]
Go through the list until you find one that works for you. Once rooted, go to the cwm tutorials.
Alternatively, you can build cwm without root, follow this guide [Only registered and activated users can see links Click here to register]
While you're at it, I recommend making a backup of your ROM and NVRAM. You will find guides in the tutorials forum as well.