iPhone 3G/3GS Baseband Upgrade/Downgrade [TUT]

iPhone 3G/3GS Baseband Upgrade | Downgrade [Tutorial]

REQUIREMENTS 3GS: Model number week 128 or LOWER.

(Upgrade)
Step 1. Put your iPhone 3G or 3GS into DFU mode.
Step 2. Launch Redsn0w. [ Windows | Mac ]
Step 3. Click "Jailbreak".
Step 4. After Redsn0w has identified your iPhone model and firmware check "Update to iPad baseband".
Step 5. If you are prejailbroken and just need the upgrade uncheck "Install Cydia" on new jailbreaks and upgrades leave it checked.
Step 6. Click "next" and allow Redsn0w to complete the process of jailbreak &/or upgrade.
Step 7. Reinstall (or install fresh) Ultrasn0w for unlock. (If downgrading for software unlock revert to downgrade instructions)
Step 8. Enjoy!

(Downgrade)
Step 1. Launch Redsn0w. [ Windows | Mac ]
Step 2. Connect your iPhone in NORMAL mode.
Step 3. Click "Jailbreak".
Step 4. After Redsn0w has identified your iPhone model and baseband check "Downgrade from iPad baseband".
Step 5. Confirm unchecking of "Install Cydia".
Step 6. Click "next" and put the iPhone into DFU mode.
Step 7. Allow Redsn0w to complete the downgrade process.
Step 8. Reinstall (or install fresh) Ultrasn0w for unlock.
Step 9. Enjoy.