The best way to get a high school diploma is to stay in school and finish. Of course, you will need passing grades and attend the required number of days in order to qualify. If you dropped out and now want to finish you have a couple of options: the first is night school where you will get the actual diploma. The second is to get a GED but that isn’t exactly the same as a diploma. It’s easier to get the diploma the first time so stay in school.