Thank you emily. But my question is not about bolt type. I have torx bits. My question might not be clear. I'm not an English native. Subaru manual (and Hynes is giving just copy of this) says I have to move "spring stopper" before removing this assembly. This looks like since this model year, 2006, EJ25 has active valve control and before this model year, these tools were not necessary. The manual says use 18258AA000 (spring installer) for moving "spring stopper". And they says also use 18354AA000 (valve rocker holder) for fixing positions of intake rocker assembly.
So, Emily, you did this on 2006 or newer engine without these tools? Does anybody have any information?