The "interesting" part of this topic lies in the risk. Unlike updating a smartphone app, flashing router firmware is a "bare-metal" operation. A mismatch in the hardware version (e.g., trying to flash V300R018 software on a V500R019 board) or a sudden power outage during the process can turn a $100 router into a useless paperweight instantly.
For 95% of HG8145V users, a manual firmware download is unnecessary. If you want better performance: huawei hg8145v firmware download better