I followed the directions in the post:
Navigate to:
/system/app: change fwupgrade.apk to fwupgrade.old and keychain.pak to keychain.old
/system/etc/security: change otacerts.zip to otacerts.old
Now reboot to recovery mode and wipe cache. Reboot system to GUI. If update appears, accept install. Countdown will appear but nothing will be installed.
The update notification will no longer appear.
1st - I don't have a fwupgrade.apk in /system/app (I even did a search for it and couldn't find it anywhere)
2nd - When I try to rename or delete the otacers.zip (in the /system/etc/security) it won't let me. It just says it can't be renamed or can't be deleted.
I am using ES File Explorer.
You must mount the directory as 'read/write' to modify.
Not sure where that option is in ES but if you have root it's there I think.
You may not have the fwupgrade.apk OR you may just not be able to see it with that Explorer if you don't have the option checked to see system/root apps.
I use Root Explorer worth every penny for me.
BUT you can use ROM Toolbox - the Lite version(free) does have a root explorer that will let you mount as R/W.