From the A1/E44 highway take the exit (no 9 I think) signed to the Airport/Senningerberg follow signs to airport to next roundabout, continue via the second exit south-west (do not go round to airport terminal). Go straight through the next set of traffic lights with the Etap and Ibis hotels to your right to the next set of lights where you turn right into Rue Kilwee. Continue 100 metres and the entrance is on your left, a lifting barrier. Press the call button and the security guard will let you in, follow the road around to your left to the front of the building and you will see the door marked reception - enter there and the receptionists are straight in front of you and will tell you where to go.
Good luck.
P.S. If arriving by air walk out of the terminal to the main road and turn left. Keep walking past the first set of lights and as above, it will take about 20 minutes.
Oops, beaten to it!