You could get a ferry to spain which takes about 3 days and leaves about once a week.
Then there's any number of ways to get from spain to Ireland which will take the guts of another week if you're travelling flat out.
It would be quite an adventure.
You should be able to get them on a flight to Madrid (Spanish Airspace is still open) from there to Santander where they can catch a ferry to the UK www.brittanyferries.com then on to Ireland by rail and ferry.