to be a little more precise, you'd need the XNA kit (free), the MC360 code (is that even published?) and the XNA dev license to transfer it to your console ($100). Plus, you;'d have to figure out how to modify the MC360 code to let you import the content, since there's no interface for it, and the MC360 code is possibly radically different.
There's nothing illegal or against ToU in that scenario because that is what the XNA license is for. It's not likely the OP is able to do so, as one who is versant in the technology would have already known all this, and wouldn't need to ask on a forum.
Even more improbable is actually hacking the X-box and modding the binaries for MC360. That is what violates ToU, and is orders of magnitude harder than the first scenario.