[L920] How do I stop my two phones from using the same account?

[Ayuk Jacob]

I bought two Lumia 920( one for my brother) but then I mistakenly used my Windows account on both phones now his phone have my contact list. when he dilates them from his phone It dilates also from mine. I really need to stop this.

 

[ramyZgHR]

Hard reset his phone and set it up again. This time, create new account.