Newer builds typically fix bugs related to slow home screen placeholder loading and initial boot-up freezes.
Firmware updates are generally safe, but any interruption (like a power loss) during the installation process can permanently damage your TV.
Copy the extracted file (usually a .pkg or .bin file) onto a FAT32-formatted USB drive.
Updates have been known to resolve "poor" image quality issues that lead some users to consider returning their televisions.
Insert the USB into the TV and follow the system update prompts in your TV's settings menu.