what size star bit is used to remove thehead on 123

[ray m]

I'm needing to remove the head on my 123 300d and i need a star bit to do it. What size do I need or is it a specialty tool. I do not want to strip them if i can avoid it.
I am disassembling the entire engine no this 1984 300d 123 Euro if anyone needs a part. I tried selling the engine and for a long time no takers. Everything on the engine is being removed including the entire block etc. Interior and exterior as well. It's harvest green, all manual interior.
I mostly need to know what I need to remove the head fo now. Thanks Ray M