You can load furniture into a dumpster by breaking it down into smaller pieces, such as separating the couch cushions from the frame. This will make it easier to fit into the dumpster and will also reduce the risk of injury and the amount of space it takes up. Use a dolly to walk the heaviest furniture first and make sure the items are evenly distributed within the dumpster. Be sure to secure any loose items well below the edge of the dumpster, so they don't fall out.