I was called to fix a leaking ball valve. First, I turned off the gas supply and carefully removed the old flex line from the stove. Then, I detached the old shut-off valve, which was worn and leaking. After cleaning the threads on the pipe to ensure a secure connection, I installed a new ball valve, applying Teflon tape for a tight seal. Finally, I reattached the flex line, restored the gas supply, and tested for leaks, ensuring everything was securely in place and functioning properly.