Arrange the sections into the configuration you think will look best in the space. The only pieces that will remain static are the end pieces. The interior sections can be arranged and rearranged until you are satisfied with the configuration.
Push the sections together. Make sure that the sections are close together as this will make coupling the sections easier.
Each sofa section will have a male coupler and a female coupler. The goal is to slide the male end into the female end to secure the pieces together. To do this, you must raise the section with the male end slightly to clear the lip of the female coupler.
Slide the male coupler into the female coupler. When you think you have the couplers aligned, slide the section of sofa downward so that the male end slides into the female end. You can check to see whether or not you were successful. The sofa pieces should be snugly connected. If not, try the technique again.
Continue the same process with the rest of the sections until each section has been secured against the rest.