How to respec / earn aditional Abiltiy Points

New info courtesy of ASPIK:
Coming after the battle but there is a possibility to respec in the game now without losing a guy.
Cost 2 retribution point and grey knight will be available 30 days.

OLD (around launch):
For reasons beyond me, the game doesn't explain the fact that you CAN actually respec your units or give them extra Ability Points.

1. To do this you first need to repair the Stasis Chamber:
   
   
2. Afterwards, you need to kill one of your units repeatedly to deplete his resilience and have him permanently die:
   EDIT: You can instantly permakill a unit by throwing him off the map with explosives (barrels or grenades)
   EDIT2: Permadeath by falling off might have been patched since I made this guide, based on what other comments are saying. I stopped playing so I won't verify it. Take it with a grain of salt.
   
   
3. Finally, you can go in your barracks, select a unit and go to the abilities tab.
   Here you will find at the bottom of your screen the Commune button:
   
   
4. Once you press it, you are given the option to give him and additional ability point or to respec his abilities. This 'costs' 1 of your dead units: