All the 3 reds (lives) go together (live feed in and out and live to switch). The 2 "real" neutrals go together (neutral feed in and out)
You have identified the switch wires and already connected the live to the switch so you are left with the "switched live" back from the switch (just to confuse you, this is probably black if twin & earth cable used BUT should have red sleeve or red tape on it to show it as the switched live return from the switch) connect this to one of your two lamp wires and the other lamp wire goes with the neutrals.