Installing Using get-player PPA
I have Linux Mint 17.3 and see in the installation notes that I'm advised to add the get-player PPA and install using that.  I've added the PPAs and done the update, but, I don't know what to do next.

As I understand it the PPAs will include all the necessary files I will need and I think I simply have to type in a command to start the process, but, I can't seem to find what it is.

Can anyone advise me?

sudo apt install get-iplayer

should do what you need.