I've been having my own fun trying out NVK on Guix System so I can't give you specific instructions (assuming you're not using Guix), but I can tell you what you need and maybe someone else can chip in on how/if you need to do anything else on your distro:

• Linux kernel >= 6.7
• GSP firmware enabled via the kernel parameter nouveau.config=NvGspRm=1
• Mesa built with the -Dvulkan-drivers=nouveau-experimental flag.

A few notes:

• Performance and stability of games has been fairly hit-or-miss for me. Of the 10 Vulkan games I've tried so far: 3 run perfectly, 3 are playable with noticeable issues, and 4 are borked.
• NVK is Vulkan-only, but performance largely comes from the GSP firmware so you will still see a difference (huge for me) in games not using Vulkan.
• You can override flatpaks to use the host's Mesa version (set FLATPAK_GL_DRIVERS=host); however, there's a bug that causes the Steam Flatpak to not work when doing this. The mesa-git-extension Flatpak exists which can also be used to replace Mesa runtimes, but it had issues building with NVK so it's currently disabled.

The only package I'm aware of at the moment (other than my hacked-together Guix package) is available in the AUR.