Xbox 360 XBOX 360 Slim DVD Drive Replacement

[NIK1]

I have a question to ask about a Xbox 360 slim dvd drive. The slim plays movies ok but not game disks.Insert a game disk and it says unrecognised disk,and after pressing A on the controller it ejects the disk.If the dvd drive needs replacing, is it easy to do. I have replaced many dvd drives in home computers and have opened up the 360 slim a year ago to clean the inside of dust and stuff. Also I have a old green halo edition Xbox in the closet that had the 3 red lights flashing on the front. The dvd drive is ok I think.Can the dvd drive from the halo edition Xbox fit in the slim. If not I will just order one. Any info on this will be greatly appreciated. Thanks...