Steps to take
1. Connect your device to your computer
2. Make sure your device is powered off, then hold down the power+volume up and down keys (you will enter a pink screen)
3. On your computer, "Removable Disk" should have popped up (if not, drivers are probably installing, so wait a few minutes).
4. Once you get into that Removeable Disk there should be a single folder titled "image". Delete everything in it and replace it with the files from this zip
5. Unplug your phone and take out the battery. Then put the battery back in and hold power+volume up
6. You should be on a screen that kind of looks like CWM but isn't, on this screen use the volume keys to navigate to "wipe cache partition", once it is highlighted tap the power button once.
7. Once that process has been completed, navigate down to "factory reset/wipe" and tap the power button for that.
8. Once that process has been completed, navigate back up to "reboot system now" and tap the power button for that option.
9. You should boot up into a factory reset version of the stock android 2.3.6 without CWM recovery installed.
hope this helps, and if it did please hit that thanks button