I have a 3GS currently running iOS 6.1 (10B141). It's not jailbroken. I'd like to update it to 6.1.2 and then jailbreak it. I'm aware that a tethered method exists for 6.1.3 but I'm interested in an untethered jailbreak. I've downloaded a 6.1.2 restore image and the evasion tool. Assuming it is possible, are there any special steps that need to be taken?