removal and replace shifter, 04 TR21x

[87gtNOS]

So how does one go about removing the shifter/throttle?
I removed the from part (the outside with the lever) and the actual control that the cables go into is trapped in the hull! How can this be removed? Gas tank removal? Or unbolt and pull out by the cables towards the rear of the boat, then replace and push back up there with the cables?

Thoughts?

04 TR21X with merc commander 4000 control...

[87gtNOS]

Here is a pic, and behind that black panel is solid fiberglass!