My wife's MacBook Pro optical drive was spinning but it wouldn't read anything. Since I do Technology Support for our school district I had taken apart MacBook Pros before, but had never replaced an optical drive before.
With the fabulous instructions on iFixit. com it was VERY easy. Put it back together and it works perfectly !
You may not have to take the "subwoofer" and Airport card completely out if you take out their screws and slide them over to get to the drive's screw underneath.