Did a job in a parkette that had this exact same situation. Our skidsteer could not lift the stone but it could muscle it around on the ground and lift 1 end of them. We just dug a hole about 4' deep and then pushed the stone to the hole. Then the skidsteer just picked up the one end. Filled in around the stone. A little pushing with skidsteer to make sure the stone was straight. Packed around stone with a jumping jack and then every thing was golden
. We did 3 of them in a grouping about 7 years ago and they havn't moved.