Selling/resetting iphone, a few questions

[ls1dreams]

Hi,

I'm selling my iPhone 4s with plans to use my old 3gs for a while, but just had a few questions for the process.

Here's my plan:

1. Backup current 4s phone in iTunes
2. On the 4s, go to general > settings > erase all content and settings
3. Connect phone to itunes and do a factory restore
4. Choose "setup as a new iphone" (are 3 and 4 necessary, or is #2 enough?)

Question at this step: I obviously don't want the 4s to sync all of my personal data in iTunes again because I'm selling the phone. When I hit setup as a new phone, do I need to stop it at some point, or disconnect it from iTunes?

5. Once done clearing 4s, connect 3gs (iOS 4.3.3) back to iTunes, and choose to restore from my 4s (5.1.1) backup.

Second question: Any issues with restoring from a newer phone to an older phone/OS like this?
Third question: Any issues with the SIM? Can I simply swap it back into my old 3gs without any activation issues?

 

[dotme]

I think this is best:

1. Backup current 4s phone in iTunes
2. Turn off/Deactivate iMessage on the iPhone
3. Remove SIM Card permanently
4. On the 4s, go to general > settings > erase all content and settings

At that point, I believe you're done.

On your second question, I believe your 3GS will need to go to 5.1.1

Whether iTunes will do that as part of the restore, or whether it's a prerequisite, I don't know - but shouldn't be an issue either way.