The steps in installing plumbing are as follows: identify the area where the new plumbing will be installed, mark out the outline of the pipe with pencil or a painter’s tape measure, dig a hole large enough for the pipe and lay down plastic sheeting to protect your floor. Next, remove any existing pipes and fittings from inside the wall cavity and place them on top of the newly cutout section of concrete or brick. Finally, attach each piece of piping using bolts and washers (tighten slowly until all fitting surfaces have contact).