Middle then moving out. The same sequence as the ALH engines. This pic should help explain it. I should really improve this pic but you get the idea. It was made with MS paint early on before I got photoshop.
The torque specs are first pre-tighten with torque wrench:
Step I = 40 Nm
Step II = 60 Nm
Then you turn further using the star socket:
Step III = 1 / 4 turn (90 )
Step IV = 1 / 4 turn (90 )
So you tighten each one 4 times in sequence. Make sure you're using the right hole head gasket, there are different head gaskets depending on piston protrusion.