I've looked around and downloaded PwnageTool and Redsn0w, but neither of them seem to have the option to bypass the "insert a valid sim" message. I don't have a sim card for the carrier the phone is on, so I'm not sure how to proceed with getting this to work. I don't know what OS the phone is running and I'm on OSX.
Any help would be appreciated!
Any help would be appreciated!