What you probably want is to re-key your cert, do not revoke it. Revoking with some CA's (such as GoDaddy) means to essentially cancel the remainder of the valid date forever and requires purchasing a new cert to secure the same domain. You are forfeiting the rest of its value.

When you re-key, it will automatically deactivate the previous cert and is free. It also gives you the opportunity to update to SHA-2 or increase the key to 2048 bit, which you should do unless you have unusual and extreme legacy support needs (and must keep SHA-1 a while longer).