Transponder casing security hex bolts?
 

I'm trying to fit the transponder that came with my new PPP ECU and the hex bolts holding the steel casing together that shields the transponder only seem to tighten with a standard hex/allen bit. If I try to undo them the hex bit just twists out so they are obviously tamper proof hex bolts.

Anyone know which bits undo these screws?

A sharp drill bit.

I actually used a dremel with a metal cutting disk and cut slots in the bolt heads, then removed with a screw driver...dead easy!