I have a a Gary Fisher 2006 Hoo Koo e Koo with what I think is Shimano Hollowtech I (one) crankset.
(Not Shimano Hollowtech II).

All the online instructions I have found point to that being a 8mm wrench for the crank bolt to be removed.

But when i put my Park Tool 8mm P-Handle hex wrench in, the whole length of the wrench goes straight through the bottom bracket.

Does anyone know how to remove it?

What is inside there, looks like the crank bolt or something is 10mm hex. But not sure.

Does anyone know how to remove this, like is it a 10mm crank bolt instead of 8mm?

2 pictures I wanted to attach. But I am new to this forum and it won't let me.

It says "Hollowtech" on the crank arms.. And also "Mega 9". And also "Shimano Drivetrain".

The bike is 9x3 speed.
Thanks