All you need is a good name brand USB drive, at least 4GB, freshly formatted to FAT32
Download the Windows RT recovery image
https://www.microsoft.com/surface/en-us/support/warranty-service-and-recovery/downloadablerecoveryimage
SurfaceRT_BMR_10.8.17.0.zip 3.033GB.
Extract the file and paste all of the folders and files
in the SurfaceRT_BMR folder to the USB stick.
Restore or refresh your Surface RT with the recovery image, booting from the USB drive.
Turn the RT off. To boot from the USB drive, press and hold the volume-down button while you press and release the power button. When the Surface logo appears, release the volume-down button. It will take a while to boot, maybe a minute or longer.
Go to troubleshooting.
Restore or refresh your Surface RT with the recovery image, booting from the USB drive.
Refresh will save your data but it needs at least 3.5GB of free disk space
and you will have to enter the bit locker key associated with your Microsoft account. Get it here
https://support.microsoft.com/en-us/help/4026181/windows-find-my-bitlocker-recovery-key may not be needed.
Restore cleans the drive.
If your restore, on the page that asks for a drive encryption key, go to the bottom of the page and select ‘Not this Drive”, tap the screen to get rid of the keyboard.
Partition selection, Select Yes, repartition the drives.
In the setup, select your color, you can’t change this later, skip connecting to WiFi, you can add your account later, you do not have to enter a password when you set the user name.
When the reset finishes, in settings go to ‘Power and Sleep’, ‘When plugged in’ set to ‘Never’. Setup anything else you need, like connecting a mouse.
Now start on the page I gave the link to'
Turn on WiFi, Search for updates from the Control Panel, Windows