When upgrading complex, interdependent driver stacks like NVIDIA GPU drivers and DOCA software, especially on a system with a pre-existing custom configuration, the most critical step is to ensure a clean installation environment. Completely uninstalling all existing NVIDIA drivers (GPU, DOCA), related software packages (e.g., CUDA Toolkit), and any custom kernel modules is paramount. This "clean slate" approach prevents conflicts from leftover configuration files, mismatched library versions, or incompatible kernel module symbols. It is the most reliable method to ensure the new driver stack installs correctly and operates with stability.

A: Installing new drivers over old ones is a common cause of system instability due to file conflicts and is strongly discouraged in official documentation.

B: Recompiling custom modules is a necessary subsequent step, but it is not the most important initial action. The old drivers must be removed first.

C: A kernel update may be a prerequisite for the new drivers, but it does not resolve the primary risk of conflicts from the old driver stack.

1. NVIDIA DOCA Installation Guide for Linux (v2.0.2), Section 2.3: "Upgrading DOCA". The guide explicitly states: "Before installing a new version of DOCA, you must first uninstall the existing DOCA version from your setup." This highlights the necessity of a clean removal.

2. NVIDIA CUDA Toolkit Documentation, Installation Guide for Linux, Section 3.7: "Handle Conflicting Installation Methods". This section warns against mixing installation methods and recommends removing any previously installed drivers before proceeding with a new installation to avoid conflicts.

3. NVIDIA Driver Installation Quickstart Guide. The standard procedure for driver installation, particularly when troubleshooting, is to first purge any existing NVIDIA packages (e.g., using sudo apt-get --purge remove 'nvidia') to guarantee a clean state.