Unjailbreak Tethered Iphone 3gs

[iMore Question]

hi there.. few days ago, i have jailbreak my iphone 3gs (ios 6.1.3) (tethered) by using the method given in the video (link iPhone 3GS Jailbreak and Unlock for Version 6.1.3 with Baseband 05.16.08 - YouTube). Now i want to unjailbreak my tethered iphone 3gs and downgrade it to 6.1.2 to get untethered jailbreak. so plz tell me how to do it...

 

[098v]

Well if you have your 6.1.2 SHSH blobs have been saved using either TinyUmbrella or iFaith and iTunes version 11.0.0 or below you can possibly downgrade but if you havn't saved them then there's nothing you can do really.
Just a side note you can't use someone else's SHSH blobs cause they're unique to every phone.