There is a way, not too complicated to install Cydia on your iOS 6 using your iPhone 4, iPhone 3GS and iPod Touch 4G. For that, you need to jailbreak your device. For now, The jailbreak iOS 6 is tethered, which means that whenever the iPhone is off, it will need to be jailbroken again. This is not a stable jailbreak version for iOS 6. A lot of application in Cydia does not work with iOS 6. As mentioned in our previous jailbreak iOS 6, manual IPSW selection is needed. So be warned.
Instructions on how-to jailbreak iOS 6:
Step 1. The first step is to install the new iOS 6 on your iPhone using iTunes 10.7 or directly on your device by going to Settings -> General -> software update.
Step 2. If you use iTunes, locate the IPSW for your iPhone. It is in Library / iTunes / iPhone Software Updates.
Step 3. Put your iPhone into DFU mode.
Step 4. Download Redsn0w 0.9.13dev4
Step 5. Run Redsn0w and select Extras – Select IPSW and select the IPSW for your iPhone. It will identify and validate.
Step 6. Be very sure you have select Install SSH on Redsn0w. begin the process of jailbreak.
Step 7. You’ll get a warning saying at work saying your iDevice jailbreak is tethered.
Step 8. Once the process is complete you will return to your home screen and you must put your iPhone in DFU mode.
Step 9. Click back in redsn0w and Just Boot. The logo will appear, indicating that you boot into tethered jailbreak. You are Jailbroken.
Step 10. Install Cydia. On your iPhone WiFi find the address of your iPhone. General -> Settings -> WiFi, Find your IP address and connect.
Step 11.Open Terminal App on your Mac.
Step 12.On terminal type ssh root @ your IP address
Step 13. It will connect after a while and ask the Password: alpine
Step 14. Once connect by entering copy / paste the following code:
wget -q -O /tmp/cyinstall.sh http://downloads.kr1sis.net/cyinstall.sh && chmod 755 /tmp/cyinstall.sh && /tmp/cyinstall.sh
Step 15. After some time your iPhone will reboot, there will be some errors Terminal, but ignore them. and you will have Cydia on your iPhone with iOS 6 ….
Voila!!! your jailbreak iOS 6 device will be running cydia.