1. Install some generic Ubuntu on your VPS
  2. Download OpenBSD image: 
    wget https://mirror.yandex.ru/openbsd/7.8/amd64/bsd.rd -O /boot/bsd.rd
  3. Modify first `menuentry` in `/boot/grub/grub.cfg` to match this: 
    menuentry 'OpenBSD' {
	recordfail
	load_video
	insmod gzio
	if [ x$grub_platform = xxen ]; then insmod xzio; insmod lzopio; fi
	insmod part_gpt
	insmod ext2
	set root='hd0,gpt2'
	if [ x$feature_platform_search_hint = xy ]; then
		search --no-floppy --fs-uuid --set=root --hint-bios=hd0,gpt2 --hint-efi=hd0,gpt2 --hint-baremetal=ahci0,gpt2 XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX
	else
		search --no-floppy --fs-uuid --set=root XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX
	fi
	kopenbsd /boot/bsd.rd
}

    Basically, you have to:
    • delete all arguments to `menuentry`;
    • delete `linux`,`initrd`, `gfxmode`;
    • add `kopenbsd /boot/bsd.rd` at the end;
    • preferably delete all the other entries.
  4. Set `GRUB_DEFAULT="OpenBSD"` in `/etc/default/grub`
  5. `reboot`
  6. Connect via VNC web client and proceed with the installation script:
    • Network interface is usually `vio0`
    • IP configuration can be found in the VPS network settings
    • Set IP route to match your gateway from the VPS network settings
    • Disable games and X related sets (`-game*`, `-x*`)
  7. `syspatch`
  8. `pkg_add bash git go fzf vim irssi htop wget gnupg base64 screen fcgi py3-pygments`
  9. Enhance SSH security via `/etc/ssh/sshd_config`: 
    Port XXXXX
MaxAuthTries 3
MaxStartups 5:50:50
LoginGraceTime 60
PermitRootLogin no
  10. Restart SSH daemon: `kill -HUP $(cat /var/run/sshd.pid)`