Step 1: First, download all the required tools and files to your Windows desktop:
Step 2: Start Sn0wbreeze, click the next â€œblueâ€ colored arrow to proceed.
Step 3: Select the required firmware .ipsw file for your iOS device by clicking on the â€œBrowseâ€ button.
Step 4: Sn0wbreeze will now identify the selected IPSW file. Once done, click the next â€œblueâ€ colored arrow to proceed.
Step 5: Now select the â€œExpert Modeâ€, followed by â€œBuild IPSWâ€ option to start creating your custom firmware.
Since building custom firmware may take some time, you can optionally play Pac-Man game to kill some time.
Step 6: Sn0wbreeze will greet you with the following â€œDone!â€ message when the custom firmware has been successfully created.
Step 7: Now follow the onscreen steps to enter DFU mode using Sn0wbreeze:
If you have followed the steps correctly, you will get the following message from Snw0breeze
Step 8: Start iTunes, click on your iOS device icon from the sidebar in iTunes. Now press and hold Left â€œShiftâ€ button on the keyboard and then click on â€œRestoreâ€ (Not â€œUpdateâ€ or â€œCheck for Updateâ€) button in iTunes and then release this button.
This will make iTunes prompt you to select the location for your custom firmware 4.3.2 file. Select the required custom .ipsw file that you created above, and click on â€œOpenâ€.
Step 9: Now sit back and enjoy as iTunes does the rest for you. This will involve a series of automated steps. Be patient at this stage and donâ€™t do anything silly. Just wait while iTunes installs the new firmware 4.3.2 on your iOS device. Your iOS device screen at this point will be showing a progress bar indicating installation progress. After the installation is done, your iOS device will be jailbroken on iOS 4.3.2.
For the unlock, you can unlock iOS 4.3.2 on iPhone 4 and iPhone 3GS using Ultrasn0w fixer for iOS 4.3.2 by following the step by step guide posted here.