打电话给Verizon国际部，说你回中国，要解锁GSM/SIM.回国后买一SIM。让Iphone 4S 连上WIFI， Iphone会问你是否要激活，答YES。
注意回美后要将中国SIM卡拿出来，否者Iphone连不上Verizon.
Verizon has confirmed (here and here) they WILL unlock the SIM on the iPhone 4S, allowing for use of local SIM cards while traveling abroad (no word yet on whether this will allow for use on AT&T and T-Mobile.) This is different than the jailbreak unlocking method; SIM unlocking through Verizon is permanent and will not affect your warranty in any way.
1. Meet the following requirements:
* Must be a Verizon Wireless customer.
* The iPhone 4S being unlocked must be active on a Verizon Wireless line of service.
* The line of service must be active at least 60 days.
* The line of service must be in good standing for the past 60 days.
* Only one SIM Unlock per line every 10 months.
If you don't meet one or more of the above requirements, call anyway. You may still get lucky.
2. Have iTunes open on your computer and the cable ready to connect to your phone (only required to confirm that the unlock is successful.)
3. Call 1-800-711-8300 (Verizon Global Support) and ask the representative for a SIM unlock. Occassionally a representative may not know exactly what you are referring to; make sure you are not transferred to a different department. You are in the right place. Explain that they should have a walkthrough on how to do this, and that it allows for the use of local, non-Verizon SIM cards while traveling abroad.
4. Get confirmation that the unlock has been applied to your account, and plug your iPhone into iTunes (don't hang up yet, in case the unlock wasn't applied correctly.) You should see a message confirming that your iPhone is unlocked.
5. Enjoy your new unlocked iPhone 4S!
