you need the follwing, Flux, soder, scrach paper and a torch. Clean the two fitting w/ plumbing sand paper or wire brush. Paint on the flux onto the pipe and the fittings where theyy meet. heat the fitting until you see the flame changes to a green flame. place the unspooled soder to the joint (make sure your pipe is hot not just melting the soder over the pipe). the soder should get sucked into the fitting. wipe area w/ a damp rag. If the joint leeks flux again a soder.
If you are talking a copper pipe and putting a fitting on the end of it that is easy. You need a propane torch, flux, lead-free solder, a pliers, a damp rag, and emery cloth. Use the emery cloth to polish a half-inch section of the end of the pipe and to clean the inside of the fitting you are going to attach until it is a shiny clean copper surface. Now wipe any grit off and smear the inside of the fitting and the outside of the pipe with the flux. Light the torch and get a good flame on it. Put the fitting onto the end of the pipe (pointing up down left or right as will be needed). Use the pliers if necessary to hold it in position. Heat the place where the pipe and fitting touch. When the flux starts to smoke touch the edge of the fitting with a piece of solder (not directly in the flame). You should see the solder melt and get sucked into the space between the pipe and the fitting. Run the solder around so that the joint is filled all around. Now take the torch away and wipe the joint carefully with the damp rag. Let it cool and you are done.
