Ok, to save your existing config, you will find instructions to perform that action here:
Browse to the location where BE is installed, default c:\Program files\veritas\backup exec\nt, and start beutil.exe!
Go to "help" and "topics". Under "contents" find "Running Backup Exec Utility Services". From that section you will find the topic "Copy Media Server Configuration". Follow the instrucions!
During installation, one option is "copy server configuration". By choosing this option, you are able to copy jobs etc. to another existing BE media server. I don't think you need it in this case!
Good luck :)