Actually, it didn't! At first I couldn't clone the HDD so I 'chatted' to the online Crucial helpline in order to sort things out. The representative couldn't have been more helpful and we managed to figure out that the brand new USB3 to SATA cable I bought on eBay wasn't working. Grrrr. (It only cost a couple of quid so it's not worth following up.) Anyway, I was able to mount the SSD in my pooter and clone directly.
Now that the cloning has succeeded, I've formatted the old HDD
and directed all my data links (such as Documents, Pictures, Music, Video and Downloads) to it. I do a lot of reading and writing to data as I'm working on it, so I think it's best to keep my data off the HHD as much as possible in order to prolong its life.
Thank you to all at PC Pals who have helped me through this procedure, especially Simon.