Final Cut HD UNINSTALL QUESTION ABOUT KEY

Hi, I purchased Final Cut HD this year, but don't use it much, so I would like to sell it on E bay. In order to do that, I must include the key. The only problem is that Im not sure if they will be able to use the key, if it is already registered in my name. When I delete an app, does it erase my connection to that key? How does this work?