See conf/default.conf and modify it to suits your needs. Better yet, copy, modify, and pass the new file as the second argument to script/databallet.sh.
Start the server by executing
./script/databallet.sh start <configuration file>.
Stop the server by executing
./script/databallet.sh stop <configuration file>.
Once installed and working correctly, executing
./script/databallet.sh update <configuration file> will get the latest scripts and source code from GitHub and restart the server.