Chosen Solution

Here’s the tool they are talking about: Mac mini Logic Board Removal Tool

that is used as a way to push the logic board out the back. all you do is

  1. make sure the back of the mac mini if facing you.
  2. make 100% sure that you have got all the screws ( the tear down missed some screws).
  3. make 100% sure that you have disconnected everything (i broke the clip to my IR sensor by not paying attention)
  4. put two screw drivers in the holes and pull towards you

I successfully used a small 2mm Allen key to detach the logic board. You shouldn’t use anything tightly fitting, since, from what I understand, it’s a levering action: fixed point is at the bottom of the case while the two holes in the logic board move to the back (connectors side). You can even get away with a single key/screw driver, if you alternate carefully.