I'm just trying to help one of the site's visitors in getting the laser diode out of a DVD-RW drive, in this case GH20NS15 DVD-RW drive
Here is a picture of the drive's sled
I have highlighted the two possible locations of the laser diode. Well, these are in fact both laser diodes, one of them is IR and one is high power red, which is what you want. it's hard to tell from the picture which is which.
You will need to use pliers to carefully pry the diode(s) from their seats - the glue that holds them is extremely brittle, with enough force you should just bend the diodes out of their seats.
Before you actually physically remove them, I would recommend testing them, at least just to identify which is the red. To light a laser diode, you will need a constant current driver, similar to the one on this page here: http://elabz.com/ttl-controlled-laser-diode-driver/
. I have a little tweezers - type connector hooked up to a constant current driver like this that I use to just touch the ends of the diode and see if it lights up. Not terribly safe for the diode (they do not like to be connected and disconnected when the driver is powered) but none have burnt at that stage so far, knock on wood.
once you've gotten the right diode out, you'll need to solder your connections, most likely directly over the existing ones. Trim the flexible cable just short of the diode and leave it on - it will help to keep the diode leads from overheating. If you are very confident in your soldering skills, simply desolder the flex cable and solder directly to the leads.
Post about any other question you may have, I'll respond here and other visitors will have a chance, too.