I would mount a 2x4 across the bottom corner, this will give you a place to put your iron leverage bar and not damage your building, the iron bar I am talking about is about 1 1/4" thick with a stab spike on one end and a mushroom flat spot on the other. its hexagonal and its strong as hell, you stab sharp end in the ground and lever against the building to get your movement. as long as your dirt is pretty hard this would work well. if your dirt is soft, you will still want the wood board along the building, but use a 2x4 and instead of stabbing in, slip under a little and lift, this will rocker the weight away from you, more work, but cheaper.
if its level, you said it is, jack it up, put 2x8's down flat, pvc on top, way less rolling resistance than soil, but you dont' want to get going too fast or be on a slope if theres only two of you. you'd need 4 2x8x10ish and use two under, two ahead and roll on. on PVC and boards, you should be able to move it by hand though.