Note : Before you do so, use itunes to upgrade your iPhone5 to the 6.1.2 firmware.
Operation steps: (In perfect)
1. Please use the latest version of itunes to back up your iphone or other iOS device. (This step is optional, mainly for just in case, if you need a quick escape, you can see the 3rd step)
2. When the itunes backup is complete, please open your iOS device, and then go to "Settings"-> "General"-> "restore"-> "erase All content and settings". (This step is optional.) You need to click two consecutive times to erase the iphone, and then the iphone will automatically start erasing all of the documents and automatically restart, and then activate the process.
3. Open the evasi0n you downloaded and make sure that your iPhone5 device is connected to your computer with a USB connection. (First open EXE file, will automatically decompression, a little wait can)
4. Open the Unpacked evasi0n folder, open and Evasi0n.exe and click the "Jailbreak" button, start patiently waiting for it, do not disconnect your iOS device during the period.
(appear in the escape in the picture below, please click on the evasi0n icon in IPhone5 to complete the jailbreak)
5. A single complete jailbreak process, please open itunes to start restoring your previously backed up files. Once the restoration completes, congratulations to you, IOS6.1.2 perfect escape success!
6. Back to your iPhone5, see Cydia ? IPhone5 IOS6.1.2 Perfect Jailbreak This completes the first refresh, and then you can turn on adding your favorite source again.