I honestly thought it would be easy to replace the shower head in the master bedroom and bathroom. The hardware that came with the shower head was just a couple of screws. It honestly seemed like a straightforward process to install the new shower head. I watched a couple of videos online and I was convinced that I could handle that job on my own without the help of a licensed plumbing contractor. I begin by putting some towels down on the floor just in case there was a small amount of water leakage. I removed the cover from the shower head and I started to remove the plumbing. None of the videos told me to shut off the water first. I did not realize that was important until water was spraying all over the bathroom. The walls were wet and so was the flooring. The place looks like a disaster. Thankfully the main shut off for the water is inside of my house. I shut off the water and called a plumbing contractor. I told the person on the phone that I tried to fix the problem on my own with very little success. The woman on the phone told me not to worry, because she would send a plumbing contractor as quickly as possible. I watched the contractor remove the shower fixtures and replace them. Other than shutting off the water, I knew exactly what I was doing. I would have been able to complete the job with ease if I had known to shut off the main water line first.