JButton btnDeleteClient = new JButton("Delete Client");
    btnDeleteClient.addActionListener(new ActionListener() {
        public void actionPerformed(ActionEvent arg0) {
            try {
                List<String[]> myEntries = new ArrayList<>();
                CSVReader reader = new CSVReader(new FileReader("Clients.csv"),',');
                myEntries = reader.readAll();
                List<String[]> toRemove = new ArrayList<>();
                for (String[] row: myEntries){
                    if(comboBox_1.getSelectedItem().equals(row[0]+" "+row[1])){
                        toRemove.add(row);
                    }
                }
                myEntries.removeAll(toRemove);
                CSVWriter writer = new CSVWriter(new FileWriter("Clients.csv"), ',',CSVWriter.NO_QUOTE_CHARACTER);
                for(String[]row : myEntries){        
                    writer.writeNext(row);
                }        
                writer.close();                    
            } catch (IOException ex) {
                ex.printStackTrace();
            }
        }
    });