top two, I have used slitting disc in my grinder, and made a slot in them into which a large screwdriver can be used to undo them. Some heat applied with heatgun to them also to soften the loctite they also use on them, and unscrew the snap bolts out.
the other lower ones I did'nt need to undo, as with the top ones undone, the top part of the plate came off and you could "flex" the security plate out of the way to with draw the ecu.
PIA to do..
good luck