How to upgrade Galaxy Nexus 4.1.1 to 4.3 It would be great if someone can suggest procedure to update the OS from 4.1.1 to 4.3 (FYI.. my phone does not get automatic update, bought it from South Korea now using in India):

Below are my phone details

Phone Model: Galaxy Nexus (maguro)
Android OS version: 4.1.1 (JRO03C.M420KRLB1)
Product Code: yakjukr
Root Access : NO


Google has provided factory image matching with my device: Factory Images "yakju" for Galaxy Nexus "maguro" (GSM/HSPA+)

Can some one please provide details how to update it to 4.3 using above factory image.

B/w though Google has provided all factory images, where does Google tell the installation instructions?
I think the easiest way is to use GNex Toolkit: http://forum.xda-developers.com/showthread.php?t=1392310