Default Moto X system version 139.4.5ghost_row_LRA.en.us

HI,
I recently got a Moto x (unlocked and system version 139.4.5ghost_row_LRA.en.us) from ebay. The original carrier was bluegrass cellular and now am using lycamobile sim card on it. It currently has andriod 4.2 on it. I like to upgrade that to 4.4 for couple of reasons. But later i figured out that there is no upgrade available for this system version.

is there any other way i can get kitkat on my device? By rooting or etc???
I read many ways to do this in internet and confused. Am not sure if this system version does matter while rooting or not. Can some one please help me out here and give me step by step instruction to get kitkat?