ok swapped parts over inc trigger and there may well be a super special way to do it but this worked
assuming you have free'd the grip frame from the main body of the ego. looking fom above you should see a small allen grub screw in the top of the trigger, this is the trigger pin grub screw- you need to loosen and remove this (don't lose it cos it's very small!) once that grub screw is removed you should be able to easily slide the trigger pin out, this will free the trigger and by easing it out from the bottom of the trigger forward into the trigger guard area it should come out- if not try loosening the adjustment grub screws as they may be restricting the movement.
If you still can't get it out, ensure you have removed the trigger pin grub screw or screwed it all the way in as although it's small it will foul it and make it very difficult to remove while it's still standing proud.
Hope that helps
A.B