How do I go about updating restoring/jailbreaking 3gs?

[iMore Question]

help restoring/jailbreaking 3gs

i have a jailbroken iphone 3gs on 4.2.1, getting no service with my tesco sim, and cydia not working properly. since its on ios 4.2.1 i figured updating it to latest ios and a fresh jailbreak might be a good start. how do i go about updating it and jailbreaking it again? which software to use for untethered jailbreak? will i run into any problems since its an old phone?
also my itunes is linked to my iphone 5, will it be a problem using it to restore the 3gs?
any help appreciated.

 

[pkcable]

Re: help restoring/jailbreaking 3gs

I don't know too much about jailbreaking and such, but iMore has a great sub forum for that stuff....

Jailbreaking, Unlocking, Hacks, Themes & Mods - iPhone, iPad, iPod Forums at iMore.com