W59 Drain/Fill plug sizing

I'm gonna swap the oil this weekend, and have searched in here for the size of the bolts for the drain and fill.

I "thought" I found a note about 24mm, but dang if i recall. Searched here, found the service manuals, but the links are dead.

So- is there a special tool needed for this? If so,can you please give some detail?

thanks,

 

24mm is correct

 

did a few more looks and found what I needed.

Went to a shop that carried Redline, was going to get the MT90. Turns out they have Amsoil there as well, ended up going w that.