iPhone 4: Use another line's upgrade?

[legaleye3000]

If I have 2 lines and only 1 of them is available for the upgrade, so I ordered on that line, but I want to really use the iPhone 4 on the non-upgradeable line (my line).

How will that work with swapping the MICRO SIM ? Do I have to get a separate micro sim from the store for my line? Thanks

 

[carmello51]

I did the same thing, and I was told to take your sim card and the iPhone 4 to an apple store, and they could transfer the numbers there and activate it for you.