Replaced the 320GB HD and the Optical drive
The hard drive was full. And the optical drive would not write CDs. I replaced both. I purchased a 2 TB HD and cloned it and purchased a replacement optical drive. I used the repair guides in iFixit.
The repair went very well. Both documents were very well written and illustrated and easy to follow.
One thing I did which helped me when I reinstalled the LCD monitor was to use sharpie pens to color code the white connectors so that I could easily tell which connectors went together.