I must confess that I was slightly nervous about taking apart my desktop computer and replacing the CD drive.
I needn't have been.
Unplugged all the cables (must remember to remove the mains power to stop me frazzeling myself) and opened up the case.
Old drive came away with removal of cables and a couple of screws.
Fitting this replacement was the reverse, however the previous drive was not a SATA drive - good job I had thought to order cables in addition to this drive (if in doubt, buy the cables as they are very cheap and you won't risk disappointment when you find the existing cables in your PC won't fit this SATA drive Wired--Up 1 SATA Power Adapter Cable and 1 SATA Data Cable
The SATA lead plugged into a spare set of pins on the main board (right next to the pins being used for the hard drive).
I then replaced all cables and attempted to boot.
I got an error message..
However the message was just saying that it couldn't find the old drive. The screen gave me all the information I needed to disable the old drive and, more importantly, to enable this new drive.
Did a save and exit from the boot screen. The PC once again started booting from BIOS level and then started normally.
After that everything just worked.
Total time from start to finish was only about 20 mins and the only tool that I have needed was a phillips screwdriver.
...and, yes, the drive works perfectly.
Highly recommended (and don't be worried about the fitting, it is really easy).