I fix lite-on CDRWs at work all the time... when someone pulls the face of a case off the wrong way, the tray gets jammed out a bit. If you trust yourself, here's what you do:
use a flathead screwdriver or something similar to wedge out the tray enough to grab, then pull it out (gently... you'll hear gears grinding but that's OK) until it stops. Then, take off the CDRW faceplate. There are 4 tabs, one on each side of the CDRW case near the front. I usually poke in the tabs on top and sides first, then bottom, but no matter which way you go the last tab will be a bit difficult to push in
OK so now you have the faceplate off but it won't fit over the tray? that's because I forgot a step... the rectangle on the end of the tray comes of by pushing each side up carefully...
so now you have the tray face and the CDRW faceplate off, and the tray all the way out... OK this will be weird but here goes... put the tray in your mouth, and bite down on it enough to get some leverage. Use a long pokey thing (i use those little bitty laptop flathead screwdrivers) and on the RIGHT side inside the CDRW, you should see a little cylinder with a tab attached to the tray behind it. Push that tab up, and with your mouth kinda pull it over they cylinder and hold it. If you don't hold it, it will go back behind the cylinder. Now you should see a relase on the far right side where the tray is in the CDRW, push THIS tab to the left, and the tray should pop out
NOW, use your finger and move the black gear (looks like 1/3 of a total gear) back and forth like 3 or 4 times. Put the tray back in, making sure it catches in the 2 spots you took it out of, and that the black cylinder coming off the 1/3 gear matches with the little groove in the tray. Put the CDRW faceplate back on, then the little faceplate for the tray, hook some power up, and it should go back in just fine. Press eject a few times to prove it to yourself.
Now, one that we had wouldn't go in ALL the way by themselves. They would go in 99% of the way and kind of make a grinding sound... all we had to do was push the the tray a tiny bit and it would work fine. We ended up using these for in house computers...
[edit]Edited for horrid tired spelling...[/edit]