This guide applies in general to all distributions that don't fully support Crossover or are unable to install all the packages that MS Office 2016 requires (e.g. you wouldn't want to layer all of them in Kinoite/Silverblue).
Prerequisite: You have bought a license for MS Office 2016 and for Codeweavers Crossover. Also you have the installer for MS Office 2016 downloaded already.
1. Install distrobox:
rpm-ostree install distrobox
then reboot to apply changes.
2. Create a new distrobox container. This should be one of the officially supported distributions for Crossover (e.g. Debian, Fedora, Ubuntu). In this example I'll go with Debian Sid because it's rolling so you won't ever have to think about upgrading your container distro to the next version.