I suggest as above go to the website and click on the personalizer and if there is something you dont want to miss out on book it as sometimes the most popular tours are booked prior to the ship sailing.
Go to p@o web site select your cruise and follow the links to your ports off call and you will find your trip.
You will be sent full tour information many weeks prior to sailing. You then have the option to either book before you sail or when you are onboard. Lovely ship, enjoy yourself.
I agree with Byers, go to the P&O Website. Click on the Before You Sail Tab, and then on Cruise Personaliser, be sure to have your Booking Reference handy, Log In, then look at Shore Excursions, provided you are within 3 months of departure, these should all be available and fully priced up. Hope this helps.