This is the Spring forum for Spring Framework questions. I am going to move this to the Beginning Java forum.
I think the main issue is how your curly braces are lined up. I can't tell how things are lined up based on your indentation of code.
I copied your code into my ide and auto-indented and found
There is a semicolon after the curly brace, it should actually be after the curly brace just above it to end the addActionListener() call.
After those lines you have two methods which are not inside your class. The second curly brace I just showed is ending your class, then you have the two methods. You need to move those two methods to before that }//end Checkerboard frame to get the methods to be inside your class.
You always need to make sure curly braces are correctly lined up
No offense, but you should never have gotten this far. Never, never never write more than 2-3 lines of code before you recompile. I have been know to recompile after writing a single line. Really you should recompile and TEST that often, but I do occasionally skip the testing part. but NEVER the compile.
There are only two hard things in computer science: cache invalidation, naming things, and off-by-one errors