Install Ubuntu Snappy Core on a computer

Take a look at http://cdimage.ubuntu.com/ubuntu-snappy/16.04/current/ which is the official server for Ubuntu releases,and you'll see that there are actually versions for AMD64 ( the 64-bit CPUs ) and i386 ( the 32-bit CPUs ). But just like with images for Raspberry Pi 2 and 3, they're .xz archives. Notice also that there is no installation software for Snappy, since it's aimed at developers and cloud, so not at average users.

So the procedure for installing Snappy on a regular computer would be actually exactly the same( or at least that's how I personally would do it with a few minor changes):

1. Download the snappy image suitable for your target computer's CPU. Make sure you verify the downloaded image's SHA-256 checksum once the file is downloaded
2. Extract the hard drive/solid state drive from the target computer
3. Connect the hard drive to another computer via USB to SATA connector. If you are trying to use really really old hard drive, you might need PATA connector.
4. If you are using Linux machine, figure out which block device is your hard drive. On Ubuntu udisksctl status command or lsblk will help you with that.

5. If you are using another Linux machine, you can use the following command ( the example shows for amd64 image just as an example, use the path to actual file that you have downloaded)

   xzcat ./ubuntu-core-16-amd64.img.xz | sudo dd of=/dev/sdb bs=32M && sync
   

   Notice that /dev/sdb is just an example, and that it's the drive device itself, not a partition like /dev/sdb1. Also make sure none of the drive partitions are mounted.

6. Place the drive back into the target machine and boot.

NOTE: you'll still need to have single sign-on account and import SSH keys, so make sure you do that even before you start installing. Read this for more info.