To use Win32DiskImager, find it on the web (here, it's free) and install it on your Windows PC. Open it (be sure to run it as administrator) and select the drive (device) that has your card reader with your SD inserted. Then in the image file box put the location where you have the extracted img file. Then when everything is set right, click on the write button. A warning will pop up asking if you want to proceed. When you have verified that you are going to write to the correct device, click on Yes. (One user overwrote their external USB hard drive by not verifying first). With this 4GB image it will take a while. If you get an error message about access denied it means you are looking at the drive with Windows Explorer. Close Windows Explorer and try again. In fact, it is a good idea to close all unnecessary windows when burning, even your browser.
When burning is complete, temporarily remove the card and re-insert again so the PC recognizes the new image.
If you do not have a 4GB or larger SD, you can use my small version of the image, also attached below. It only requires 120MB of space on the SD. And it has all the same features as it's bigger 4GB brother, it is just smaller. But there is not room to put backups on the card. If you use a small card, see item 11 below for workarounds on making backups.
You can use partitioning software, like Mini-Tool Partition Wizard or EaseUS Partition Manager (both free), to can expand the partition to the full size of the SD you burned it to. But I recommend you not use a really large SD to put CWM on. Certainly no larger that 8GB. It is a waste of a big card to use it for stock CWM.