Complex sentence: He climbs all the way to the top, unties the rope, and frees Lumpy, who is very happy that Roo had rescued him, and Lumpy and Roo hug.
Split into simpler sentences: He climbs all the way to the top. He unties the rope, and frees Lumpy, who is very happy that Roo had rescued him, and Lumpy and Roo hug.