Stump this chump, 99 300td head removal

[oldwheels]

I'm trying to take the head off my 99 300TD. The cam cap bolts are a bit strange and I see no mention of what they are nor special tools.
These are 12 point heads that measure 10 mm across the points. I'm thinking a 9 mm 12 point socket may do the trick.
Anybody have any ideal what these are??

Yes, I guess I have a blown head gasket. No 1 cyl is low about 320 psi but leaks down quickly. The others are happy at 430 psi.