Yes, this is a do-it-yourself job. Aside from the copper piping, you will need some steel wool or fine emery cloth, a pipe-burnishing brush, flux, solder and a propane blowtorch. Clean both parts of the piping that will be joined with the steel wool or emery cloth. You can clean out the inside of the larger pipe with the pipe-burnishing brush. Before joining the two pieces together generously rub flux on both pieces. Flux is designed to oxidize the copper and help pull the solder into the pipe and make the connection more secure. If you do not use flux, future leaks are guaranteed. When soldering the two pieces of copper together do not make the mistake of melting the solder with the blowtorch. The blowtorch should be used only to increase the heat of the copper. Once it is hot enough, the solder will easily melt when touched to the surface of the pipes. If the piping is close to a wall make sure the wall is protected by a heat pad, and remember to wear safety goggles.