This script installs and configures xfce, slim, slim-themes and consolekit2 on a freshly installed OpenBSD 6.3. The installation of xfce-extras, paper-gtk-theme and paper-icon-theme is optional.
Copy the script via scp to the OpenBSD machine.
# scp xfce-install.sh root@openbsdmachine:/root/
Run the script on the OpenBSD machine and remove it at the end. There is an option to use a different package mirror. Go to https://www.openbsd.org/ftp.html and choose the URL you want and enter the URL.
# cd /root/
# ./xfce-install.sh
# rm xfce-install.sh