As the others have said, take a philips head and go to it. It just comes right off. On my 272LE, I cut the power wires to the red LED in the compass and spliced in connectors. If you don't have a connector, add one like I did. Make sure you keep track of which wire is which, as the LED won't work if you get them mixed up (ask me how I know).
What's up with the linkage? Why do you have a need to check under there? The adjustments to the cables are on the other end, at the steering quadrant. Tough to get to in the 272 but very doable.