Close the main valve to stop the supply of water to the area where you wish to install new plumbing. Open a stopping valve to drain out the contents of the pipes. If you cannot locate a stopping valve, open a few taps to release all stored water from the pipes.
Use a bucket beneath any pipe that you wish to cut, place it under the pipes and cut the pipes so that the water drains in the bucket. After the dripping has been stopped, use a piece of cloth to dry the pipes.
Buy sand paper from a nearby hardware store and use it to clean the copper wire till it becomes shiny on the outside. Clean out the inside of valve or any component that you want to fit in your plumbing system.
After cleaning out the inside of the coupling, fit it inside the pipe. Use a propane torch to heat the joint between the pipe and the fitting. Remember to add flux to the fitting, and when the pipe is hot enough, apply soldering to it.
Touch the flux with the tip of the solder, then move the solder over the pipe to close out any gaps between the pipe and the fitting. Repeat this step for all other pipes and fittings in the area till the water supply to the desired area is restored.
In case of metal piping, use a pipe wrench to open joints for the installation of new plumbing. Fit in the new pipes and cut fit them to the existing piping with the help of the threaded adapter.