OK, so you managed to install iOS 5 with custom firmware, but irritatingly your WiFi is broken and you’re not able to download ultrasn0w via Cydia. Don’t worry, you can still unlock your iPhone 3GS.
Your device should already be jailbroken by now, because that’s a requirement to unlock your iPhone.
If you haven’t jailbroken your iPhone use this instruction. Do everything until step 17. Done? Then let’s continue below.
2. Launch i-FunBox or DiskAid and go to /private/var/root/Media.
3. Inside Media folder create a folder called Cydia.
4. Now inside Cydia folder create an AutoInstall folder. Note: The folder name is case-sensitive so be sure to name it accurately. It should look something like this:
6. Reboot iPhone (remember it’s currently boot tethered! So start redsn0w > Extras > Just Boot).
This tutorial will also work if you have an iPhone 4 baseband 1.59.00.
Good luck and leave any comments or questions below.