Different Ways Mercury Will Be Made Habitable
Water
Since Mercury has Oxygen in its atmosphere, if we brought in Hydrogen, our specially trained scientists could create a chemical reaction causing the result to be water. Since water is H2O (which is one hydrogen molecule, and two oxygen molecules) it creates water.
Food
Our scientists are going to genetically alter some food plants and seeds, so that they will grow in any type of soil. Since the scientists are going to have water, we will water the food plants daily, and the Sun will prvide much sunlight. The plants will be grown in a planthouse, so they don't get too much Sun, and so they get more oxygen. How will that get them more oxygen? We will provide the planhouse with twice as much oxygen as a normal planthouse, so the plants will never run out of nutrients.
Gravity & Oxygen
For Gravity issues on Mercury, our scientists will all provide everybody with suits. They will be cushioned, and control your body so that is doesn't fly off. It will also help with the oxygen issue, by controlling the amount of oxygen you get within the suit. This suit will have to be worn at all times.