</font><font color="blue" class="small">( I've moved many a tree with my backhoe, some much larger than your sizes. )</font>
I've dug many that size or bigger by hand. It was a real PITA, but still took less time than it would probably take to build one of these.
Or you could contact a local landscaper who has a spade; he may be willing to dig for a fee, or in exchange for some of the trees.