Help X and eris ?

[bcltoys]

I have a X my wife has a Eris I was thinking of giving her my X and getting another X do I activate my old X on her number the same way as I would when switching between phone's on my own number i/e turn old phone off and activate my old X phone on that number.

 

[JrzDroid]

You have to put your number on another phone then *228 on the X and input her number.
Smartphones don't need to be off either to switch