You'd have to copy the files to their designated paths. I've laid out the files so that just copying all the dotfiles - and directories - in the repository to your ~ should be enough to load all the configuration files. You'll also need to install all of the programs and fonts used in this configuration (in the repository's README.md) to make sure that everything works.
That should be enough to set it up, but let me know if I can help you any further. Oh, and the configuration files are pretty old, so you might need to adjust them to account for any changes made to the programs they're used for.
I’m now using Hyprland on NixOS (have been happily doing so for months now) after a configure several other window managers (leftwm, awesomeWM, etc.).
I plan to share my setup sometime soon but I’ve got secrets in my configuration (and git history!) that I’ll need to remove first.