From blog post Arch Linux on The Surface Pro 4. Created for Jordi Higuera
If you do have access to a hub, and you have physical access to the machine, letting you plug a keyboard in, you're probably better off using a fresh install ISO. From the Arch Download page download an up to date ISO.
If you've already gone through the steps of shrinking your SSD to give you some extra room on your SSD, once you've booted in to the ISO run lsblk
you should see something like this: