In case you want to become a bathtub replace through apprenticeship, you will have to approach the local plumber's union, who can help you to find a professional plumber willing to hire an apprenticeship.
If you find that the water line repair leak is in the supply line you will need to replace it or simply tighten it. Start by turning the water supply off and then flushing the toilet to get rid of the excess water. Now use the towels to dry the area so that it is easier for you to fix the leak. Use a wrench to loosen the hexagonal nuts on the supply line at the main end as well as the one which goes to the flush tank. Now use the replacement supply line which you have and tighten the bolt at the supply end first. Now adjust the length that you will need for the pipe to reach the flush tank. Once you adjust the length use a knife to cut the extra length and then tighten the hexagonal bolt at the other end.
After you have the stems out you should be able to find the washer on the "inside" end. If it is nicked, torn or brittle it is likely the cause of your drip. Even if it looks brand new, go ahead and replace it. You've already come this far. You can get replacement washers at almost any hardware store. Sometimes you may want to replace the whole stem, especially if the handle end is stripped out. It's best to just take the stem with you to the store and see if you can match it up. Most Do It Yourself stores have replacement stems for many popular brands. If your valve has a center diverter valve to switch the waterfrom the tub spout to the shower head the same process applies. Many times it is easier to replace the diverter stem than to repair it. This really depends on the design of the stem.
Dirty waste water, after all, leaves your house following the law of gravity. Waste water goes downward to the sewer or septic tank, nice and easy. Behind this simple rule is the multitude of vents and traps to keep the process of waste removal possible. Vents allow air to fill drainpipes, precious air that allow waste water outflow. Traps are those curved S-shaped sections of the pipes under the sink drain. Traps perform a crucial role in forcing most of the water through the drainpipe, but leaving some to seal the area and prevent sewer gas from backing up.
If the area around the fan isn't clean and dry, or if dust or any sort of growth has accumulated on the blades or inside the exhaust duct, it may be a warning sign of excess moisture build-up. Clean the water line repair fan and area well. Then double- check that the fan is operating properly.
And the way to know what's sufficient? Well, until the work is done an the bill paid you won't know for certain, but this is the best that can be suggested and normally works very well.
Plumbers can help keep small problems from becoming large problems. Do your homework before choosing a plumber and you can help to ensure that the job is done correctly and for a good competitive price.