Do I have to root/Risk warranty to downgrade from LPOP 5.0 to Kikat 4.4? note 4

[vlaregbon]

I have a Tmobile Note 4 and since upgrading to lollipop my Simpsons Tapped out game has been EXTREMELY LAGGY!!! So I wont to revert to kikat BUT do not want to root to risk losing Tmobile warranty. HOW DO I do this????!!!

The only way I know to revert is using Odin, however the process seems similar to rooting. Is there another way??