The DVD drive is not hard to replace at all and they don't cost that much either. You can easily swap your current one out with a new one within 15 minutes.
I am not sure if your PC has an "IDE" or a "SATA" DVD drive. Find out before you buy a new one. Below are 2 low priced but good drives from Amazon.
SATA -
http://amzn.to/LG-DVD-RW-SATAIDE -
http://amzn.to/LG-DVD-RW-IDE PLEASE NOTE: I am assuming you have Desktop. If you have a laptop you must order another one through your laptop manufacturer. The price will be kinda expensive too.