Prevent Baseband update after Spirit Jailbreak

MuscleNerd (one of the iPhone Dev-Team) posted some tweets for how to prevent Baseband update after Spirit jailbreak using a method called "last-ditch" for those who ignored warnings on SpiritJB.com to not use Spirit if you're using blacksn0w on an iPhone 3GS without 3.1.2 SHSH blobs on file.This is not a jailbreak or an unlock by itself. It's much safer (that method has the potential to brick your baseband if your timing is off).
Some People who were using blacksn0w on their iPhone 3GS at 3.1.2 tried to apply the Spirit JB without removing blackra1n. They found themselves in a reboot loop or stuck at the Apple or recovery screen.

Note:Do not use this method if Cydia has your 3.1.2 SHSH hashes on file – it's overkill! Just restore to 3.1.2 using your saved hashes instead. (But if you've already got 3.1.3's baseband on your iPhone, it's already too late for you and you must wait for the next unlock. This method doesn't change that.).

Requirements:

• Using iPad 3GS
• No 3.1.2 SHSH blobs on file with Cydia (or locally on your computer)
• You've never updated or restored (or bought your iPhone with) stock 3.1.3 before
• Have access to a SIM card that will allow your iPhone 3GS to activate through iTunes.[Important]
• You're currently in a reboot loop or stuck in recovery mode. If you're not, You may want to leave well enough alone for now.

Steps:

1. Make sure you have rslite or iRecovery handy and that you can run it. You'll need to use it after iTunes errors out.
2. Unzip the 3.1.3 IPSW. You'll be making three changes to it.
3. Remove Firmware/all_flash/all_flash.n88ap.production/LLB.n88ap.RELEASE.img3
4. Edit Firmware/all_flash/all_flash.n88ap.production/manifest. Remove the first line (LLB.n88ap.RELEASE.img3) then save back the file.
5. Remove the two references to LLB in BuildManifest.plist. You want to remove the lines starting with LLB up to and including the next (this will be 17 lines). Do this twice…once in the first half of the file, and once in the second half.
6. Zip it all back up. Keep in mind that the top-level of the zip should be that directory where BuildManifest.plist is. (Don't zip it from the folder one level up from this by mistake).
7. Restore or update to this modified IPSW (not the stock one from Apple!). It will eventually error out (error #6).
8. Use rslite or iRecovery to get past the subsequent recovery screen. Using rslite, you'd do:

% rslite
rslite v0.2 - by the iPhone Dev Team, 2009.
--THIS IS AN UNSUPPORTED TOOL--
Connecting...
[Recovery] setenv auto-boot true
[Recovery] saveenv
[Recovery] reboot

Need Help:
Sure feel free to ask what you want here by adding a comment or by asking MuscleNerd on twitter [Thanks for Jasmine_Joel for heads up by tweets]

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