How to I get Sprint Galaxy S4 to At&t with MSL code?

[AC Question]

I got the MSL code for my phone from Sprint, I took the phone to AT&T store yesterday (forgot the code home but the guy said I should be able to put it in easily on my own at home). At&t guy did his part and handed me my phone back. When I got home I realized there is nowhere to put MSL code to. I called to ATT customer service they asked me to dial ##3282# . It did ask my MSL there but that's it, I don't know where to go from there. Please help me.