The addon needed is MK Studios Dublin Airport (EIDW). You can find the addon at Orbx or simMarket.

Here's the (basically) completed GSX Profile for EIDW Dublin Airport by MK Studios. 

All parking stands modified except for two GA spots which I'll get to.

 - Custom vehicle positions, marshaller positions, cargo vehicles and cargo loaders on every stand. 
 - Custom pushbacks with majority having multiple waypoints so the aircraft can better follow the pushback taxi line.
 - 23 custom PAX walkways with multiple waypoints and majority of PAX leave through doors from the terminal for a more realistic effect
 - Adjusted aircraft's position on the stop lines to ensure jetways actually reaches the door.

Tested heavy gates with the 878
Tested larg and medium with 738, 737 & A320 FBW.

Current SU9 issue: Pier 2 custom jetways (the blue and green) will show PAX walking from an increased height from the jetway joint to the correct height at the jetways door. It's a know issue for some 3rd party addons and SU10 will allow FSDT to apply a fix or workaround. Other generic jetways in the airport work fine.
You can see the PAX heads just poking through the roof of the jetway which is not that terrible. The affected jetways are 311 to 318

Installation: 
Extract the zip file and move the .ini file to %APPDATA%\Virtuali\GSX\MSFS

Don't forget to disable EIDW Jetways in GSX configuration. Great tutorial can be found by easysimjetpilot here: https://www.youtube.com/watch?v=LixUZeCizKQ&t=613s&ab (ignore the AFCAD file path part, the FSDT dev advised the path doesn't need to be changed)

As always, because I've got a very simple brain, there may be errors or small changes needed. Just let me know.

Gav