Hi des,
You can avoid the tunnel and 2 tolls by turning left when you come out of the port, (look for the signs for south Dublin and not the M50)
When you pass the 02 venue (was called the point depot) at that mini roundabout turn right keeping the river Liffey on your left, note the speed limit is something stupid like 30kph on this stretch of road by the quays, follow this all the way, you cross the river and then it will be on your right, from there follow the signs for M4 (west) and that will bring you to the M50 junction,
Take the M50 south bound to the next exit (Naas road) signed for Limerick (M7) follow this road keeping an eye out for Bewleys hotel new lands cross, (roughly an Irish mile from M50) you will be taking the next exit off dual way, keep an eye out for the brown sign with camac valley on it,
If you see a brown sign in Ireland it's usually info for visitors leading to accommodation attractions etc, (but you have to find the pub your self
)
Hope this helps, and I hope enjoy your trip to Ireland
