$ sudo apt update
$ sudo apt list --upgradable
$ sudo apt upgrade

$ sudo vi /etc/apt/sources.list.d/nvidia-l4t-apt-source.list

deb <https://repo.download.nvidia.com/jetson/common> r32.5 main
deb <https://repo.download.nvidia.com/jetson/t194> r32.5 main

$ sudo apt update
$ sudo apt dist-upgrade

YES enter, enter, enter....

$ sudo reboot

$ uname -r

4.9.201-tegra

$ jetson_release

- NVIDIA Jetson AGX Xavier [16GB]
   * Jetpack 4.5.1 [L4T 32.5.1]
   * NV Power Mode: MODE_30W_ALL - Type: 3
   * jetson_stats.service: active
 - Libraries:
   * CUDA: 10.2.89
   * cuDNN: 8.0.0.180
   * TensorRT: 7.1.3.0
   * Visionworks: 1.6.0.501
   * OpenCV: 4.1.1 compiled CUDA: NO
   * VPI: ii libnvvpi1 1.0.15 arm64 NVIDIA Vision Programming Interface library
   * Vulkan: 1.2.70