You don't want to do that.
You may be able to reach the nuts with a very long handle drive extension, can get the flexible spring like one.
Tape the parts together incl socket so you don't loose them.
If not - like Brian wrote
Small pry open inspection plates are the normal on many boats even new ones, can even get matching off white or ivory color, smooth surface or pebble/cross hatch, etc. Use only a hole saw to cut opening, select size no larger than a hand needs to fit thru it. Caulk in place. Older Gradys used TEMPRESS MARINE hatches, can find their website if you Google it. Ivory is their color match.
Wait until you have to do fuel lines!!!