Default Sim Card Question...

Going to change from Sprint to TMobile...Sim card cums tomorrow...Im rooted running kit kat 4.4...Do i need to go back to stock to be able to set up new Sim Card...i was going to Odin back to MJ 14...Is it neccesary for me to do that...???
My Ex Phones
HTC Touch
HTC EVO
HTC EVO 3D
Galaxy S2
Galaxy S3
Note 2

Galaxy Note 3
Runnin Any and every Custom Rom...(Flashaholic...)

Galaxy Note 8.0
Running Civ-Z-FlexNote 8.0 4.2.2 KK Rom (GT-5110)
Custom Kernel ???

Soon to Purchase Note 4...Hopefully in September after release...)