Well, of course it's "compricated"! You would take a ritual bath, put on a white robe, write a death poem , drink a ceremonial cup of sake, all before you could even start with the disembowelment!
No one said it was simple.
Here's a poem for the ceremony:
The boss said, in tones dark and dreary:
"This time, Didge, you DO hara-kiri!"
But the boss hadn't reckoned
Being named Didge's second,
And QUICKLY tossed Bushido theory.