We are due in Civitavechhia on our next cruise and have been looking at various ideas as to the best way to get into Rome and back to the port. As this will be our first visit to Rome, we realise that the safest way is NCL's own tour after getting off the Epic. However, as they want around £70 just to take into the city and back on a bus, we have been looking at alternatives. 

Our plan is to get the shuttle bus to the outer gates of the port of Civitavechhia, and then walk the 15/20 minutes to the train station. Book a €5.00 ticket  to Rome and get off at Ostiense. Walk the short distance to the Metro stop of Piramide, take 2 stops to Colosseo (€1.50) and start our own tour at the Colisseum. We then intend to slowly traverse the city, taking in the Roman Forum, Spanish Steps, Tivoli Fountain, and then finish at the Vatican. The plan then when our half day is finished is to walk down to the  regional train station of Roma San Pietro and then back to Civitavechhia, and a quick walk back to the ship.

My question is, has anybody else done this trip (or similar) themselves , and is it an easy option. Any help would be very useful