As you can see, the brake lines for this particular product are all together, so removing a specific one is difficult at best. This is not a case for a neophyte, but should be handled by a competent and qualified brake mechanic. Getting a car to go is easy. Getting them to stop is life-threatening. However, if you insist I first have to say if it were me behind the wrench, this is what I would do, but you might not. In other words, if you crash, I am not taking responsibility. Do this project at your own peril and risk.
You are going to have to get to know a person that works in hydraulic lines. You will need a compression fitting, a line bender and crimper and a rubber hose that will go from the piston connection to a female connector. Basically you find where the leak is and remove that portion of the line and with the crimper and other parts, you put the female connector on the line that failed. From there you connect the rubber male end to the repaired line to the piston connection. Keep in mind, this is probably a temporary fix at best. Most of the time, when you replace a part of the line, the best way to do it is to replace the complete line, but since the Hyundai is an all in one welded together, you have a task ahead of you.
Again, since you have to ask, this shows that this entire procedure is levels above your mechanical skills. I am not saying this to be rude but this repair needs to be done by someone that can be held accountable when you go over dead man's curve. I would spend the extra bucks here. Then again, carburetors are magic to me. Thank god for fuel injection.