Open JBuilder and select 'open'. Browse to the files you want to open ( you will open .java files, not the corresponding .class files ). That's pretty much it. Although, I would recommend opening the .java files in TextPad or NotePad first, and compile from the command line. Until you at least can compile from the command line and write code in a text file,
you should stay away from GUI development tools (I'm only talking about 2-3 days, though). After you've done your first 'hello world' program from the command line, then start using JBuilder. That way, you understand what is happening 'behind the scenes.' Just my two cents!