Update : A much faster easier solution for Mac users can be found here. Windows users may resort to ZiPhoneGUI.
I am back after spending 4 hours on the entire process (which includes some hits and misses! Which means, you no longer have to figure out the right steps/combinations!!). Now the process is trimmed down to much lesser time and the best part being : No command line hackery!
All you need is an iPhone (OTB 1.1.2/1.1.3 BL 4.6), Mac (preferable) / Windows, Firmware files (1.1.2, 1.1.3 ipsws), courage to try this …