Samsung has begun the official Android 4.4.2 KitKat update rollout for the Galaxy Note 3, but it's going to be a while before every variant of the device and every country receives the update. If you've got the a Galaxy Note 3 from carrier Telcel in Mexico, with model number SM-N900W8, and are unwilling to wait for the official update to arrive, then you can try out a leaked firmware instead. Leaked by the folks over at AndroidMX, the firmware comes with build number N900W8UBUCNA2 and is an official pre-release build from Samsung, which means it will not void your warranty or trigger the KNOX flag.
The update includes features like faster performance, lower memory usage, white status bar icons, ability to choose default messaging and launcher app right from the settings, built-in wireless printing support, and more. You can flash the firmware using Odin, though you should backup all your data before you proceed to the source link to find the necessary instructions and download links for putting the ROM on your Galaxy Note 3.