BB1 green MPU - how to remove CPU heat sink?

[Paladin]

I have a dead BB1 blue MPU, and all you need to do to remove the CPU heatsink in order to apply new thermal paste is release the tension wire.  Unfortunately the replacement green MPU I just received is not so simple.  I can see that the heatsink is screwed down from underneath, and uses one of the adastra board attachment points.


I'm assuming that someone here has removed a heatsink from one of these boards, and I'd appreciate any tips!


I can't tell if you simply remove the adastra board then flip it over to access the two screws holding the heatsink on, or if you need to take the entire MPU board out of the metal cage.  If the latter, I'm wondering if it's worth the trouble when you consider how that would increase the odds of damaging something (slot humor).  It really looks to me as though the one corner of the adastra board and the heatsink would need to be screwed together from the back of the MPU.