Geezus, how tight are these torx bolts? I'm in the process of trying to swap rotors. I've tried with a half metre breaker bar but fark me.

Heat them up first is the easiest way.  I usually use an impact driver for the first hit, but most people don't bother after heat.  Easy.

Thanks I'll give it a crack

The last rear rotor I changed I had to use an oxy to break them loose.
My rattle gun wouldn't touch them !
obviously need new bolts afterwards !

Heat and sharp impacts usually do it for me. Some more so then others.

Heat gun to get those scrubby barsteads off, as above.

AND...throw the bolts away as they come out. The OEM bolts are a torque-stretch design that elongates as they are removed. They are designed to exceed their elastic limit on installation, it's a kind of mechanical Loctite. This is why they're a bastard to back out even after the head cracks. The bolt pitch once-removed is nothing like the internal thread. The MoCo manual is quite clear on this.