Software for this board is typically hosted on specialized technical forums. You can find firmware versions and discussions on: KenotronTV : Often hosts the exact USB firmware for this TP.MT5522S.PC822
all parts of the RAR (including Part 07) into one folder. Copy the .pkg file to the root of a blank USB drive. Unplug the TV from power. Insert the USB into the TV.
The main file inside the archive is usually named allupgrade_5522_8G_1G_ref30.pkg . How to Install
The text you are looking for relates to the for a Polarine 43PU11TC-SM
Updating firmware is risky and should only be done if your TV is stuck on the logo, restarting, or has software bugs.
RAR archive (specifically "Part 07," indicating it is part of a larger multi-volume download). Where to Find the Software
on the TV (not the remote) and plug the power cord back in.