I have one key on my piano that when you press on it, it becomes louder and more accented than the rest of the keys, and when you play songs, it sounds terrible. I want to learn how to fix the key myself because I don't want to spend 400 bucks to have a piano repairman come to my house and fix it. Does anybody have any information or solutions?

First thing to do is change your username, you're creating negative mojo with a name like NoSkillz. I took apart my P140 and fixed a sticking key, the hardest part was separating the case halves. I'm not familiar with the Clavinova, I suggest just start taking things apart. Worst case is you screw it up and have to call a tech, which is exactly where you are now.