Gosh, ARM devices are different from x86 ones. Almost all ARM devices are vendor locked. If you are interested in knowing how to do this on a Surface Pro (A.K.A a x86 device), I can help you out.
> Almost all ARM devices are vendor locked.
It seems I have an odd sample over my desk. There are 4 ARM-based devices on it, all of them are unlocked.
Your Surface RT(if you really have one) does not come with a Windows 8 Certified Logo sticker.