Adjusting Input Current Limit, Using GX50 Touch

With a hybrid inverter/charger system, like Victron's Multiplus series or Magnum's MSH, it's necessary to adjust the system's "Input Current Limit", essentially letting the system know how many AC amps are available to use for charging and running AC loads inside the coach. Too high a limit, and the inverter/charger will try to pull more amps than available, simply tripping the breaker you're plugged into. Too low, and you're leaving power on the table!
Plugged into a 50amp service at an RV park? Adjust the limit up to 50 amps to take full advantage of all that available power.
Plugged into your 20amp outlet alongside your garage? Adjust the input limit down, to prevent the system from pulling more amperage than is available and tripping your breakers.

[@charlieodom9107]

What do you do if the input current limit option is locked and won't let you change it?