Removing jailbreak without downloading firmware again?

[vitaminz]

Hi all, my girlfriends' sister has an 8gb 3G which is having some hardware issues, but before she takes it back to the Apple Store I suggested she restore the phone to get rid of the jailbreak. Now problem is, she doesn't have an Internet connection at the moment at all at her home, so iTunes won't be able to download the relevant update files.

Can anyone offer any advice? I was thinking that 'Erase All Content and Settings' may help, but can anyone clarify exactly what this feature does, and whether she'll still have to plug it into iTunes and whether it'd remove the jailbreak?

Thanks

 

[Applejuiced]

Not possible.
If u do the erase all the phone will be in restore mode and won't even boot up.

 

[spinstorm]

The jailbreak will still be there.

The ONLY way is to restore to original firmware.

Just Download the firmware for her onto a USB stick or SD card and copy it onto her PC/Mac then select shift + restore or the sideways N + restore on Mac and select the 3G firmware.

But keep in mind without the Internet connection it won't activate.

I'd suggest she comes over to your house and does it there! Simpler isn't it?