Flashing DVD+R drive to DVD+/-R

​ I have an Inspiron 9100 with a CD/DVD drive that reads and writes CD's, reads and writes DVD+R's but only reads and does not write DVD-R's. I've read that it may be possible to "flash" my existing slim drive so that it will also be able to write DVD-R's. I understand that it's a somewhat complicated task that often can't be undone. That said, does anyone know what I need to do to "flash" my drive? I'm not too worried about having a broken drive later since the LCD display on this notebook just failed (backlight I believe). This notebook is no longer under warranty. Lastly, in Device Manager, my drive is listed as "HL-DT-ST DVD+RW GCA-4040N". Any assistance is greatly appreciated! Thank you! ​