Scroll down the page - in the section MIRROR SITES. Pick a download location. Save the ISO file.
Use the other link to create the bootable flash drive.
You will need to access your boot menu in the Surface to explicitly tell it to boot from the USB device.
I saw this info online, but I don't know which model you have, so you might have to search by your exact model ("surface xxx boot from usb")
Insert usb bootable flash drive
Hold the volume-down button.
Press and release the power button.
When the Surface logo appears, release the volume-down button.
The Surface Pro should boot from the attached USB device.
"Living tomorrow is everyone's sorrow.
Modern man's daydreams have turned into nightmares.