Short answer, nope not doable.
Surface 2 with Windows RT uses an ARM CPU chip like that in a iPad which is incompatible with Intel x86. There was never a Windows 7 RT version and Win 7 x86 is not going to run on the Surface 2.
The only two versions of Windows in the "RT" flavor are 8.0 and 8.1. There will be an update with some W10 like capabilities although we do not know what it will have or what it will be called (bastard child).