I'm on Tmobile right now, and plan to stay on tmobile through the end of the year. I might switch to Verizon early next year depending on where I end up moving. I can pick up a new in box 7 Plus Verizon version right now. Will I have any issues just putting my Tmobile sim in it or do I need to have him open it up and put his Verizon sim in it to activate it?