Speak to High Guard Mavaerick on Windgazer's Hideout at ( -661, 8, -498 ) Copy/waypoint -661, 8, -498. If he is not present, then you must free him from Prisoner's Isle at ( 570, -111, 58 ) Copy/waypoint 570, -111, 58. After killing all seven pairs of Blacktalon wing clippers on the isle, he will fly away and spawn on Whisperwind Isle.
These are ground spawns throughout the zone. Each major area of the zone holds one type of egg. So when you find one, you can move on to the next hall/room.
Make sure everyone in the group has picked up 6 eggs before killing Chamberlain in the last room. The next step is to kill him, and if you don't wait 5 minutes for respawns you'll be waiting 90 minutes to reset the zone.
Three eggs spawn at a time. They have about a 5 minute respawn timer, so you might want to pick up half on the first run through, then send 3 people back to get their updates before killing Chamberlain.
In order to get to the last level you have to get a key to the lift. This is called A strange crystal egg. It drops from either Switch or Nutty who patrol with a group in The Library of the Seven. ( -20, 56, 1 ) Copy/waypoint -20, 56, 1