The answer to 'how to clean water line replacement' is to thoroughly flush and disinfect the new water line before use. This involves running water through the line at high pressure to remove any debris or contaminants, then treating the line with a chlorine solution to kill any bacteria.
Begin by turning off the main water supply and opening faucets to drain the system. Next, attach a hose to the new water line and run water through it at full pressure for several minutes to flush out the line. Then, mix a chlorine solution of 1 cup of household bleach per 1 gallon of water and pour it into the line. Let the solution sit for 30 minutes before flushing the line again with clean water until the chlorine smell dissipates.