The plumbing courses cover all the aspects that you will be required to deal with as a water softener. You will be taught about the basic aspects as well as about health and safety issues and sanitation.
There are two, one on each side of the toilet, closet bolts which hold the toilet to the floor. If there are caps over the bolts, remove or pop them open. Using a small crescent wrench unscrew the nuts from the bolts. Alternate side to side when unscrewing this will be much more important when reinstalling the water line repair bolts but alternate anyhow.
Leaks can occur anywhere in your reverse osmosis water filter system. If this ever occurs, check the source of the leak. It may be from the hoses, fittings and the valves. Most of the time, some kind of tightening might be necessary. So make sure to securely tighten the fittings. If this does not work, you may need to replace the filter itself, however that might take a bit more work.
Once you have disconnected the tank remove it from your work space. Do a thorough measurement of the remaining pipe for reference when you go to the hardware store. I will be honest with you, you might need to make a few trips back to the store. Once you get the new tank, slide it into place to line up the plumbing.
The water line repair most likely damaged your electrical outlets and lighting fixtures. Have a qualified electrician come in to evaluate and repair the electrical.
Keep your hands clean and dry. Plumbing jobs get slippery, so it's important to work with a pair of sturdy gloves so you don't lose your grip and accidentally hurt yourself or break something.
By the time that you have made your pick, make sure to check ID and Certification. Remember, these individuals will be doing their works inside your home. The security of your family is also an issue here. If they can't present any papers of identification, then don't take them in! When it comes to your family's safety, there's no room for experiments.