Flip the circuit breakers to shut off power to the elevator trim motors. The elevators can be controlled by the pilot’s yoke and the elevator trim will have to be set manually or it will not work which means the pilots will have to fly the aircraft by hand without trim assistance. That’s what the yoke or “stick” is for.
“The preliminary report into the Oct. 29 of a Lion Air Boeing 737 MAX 8 crash confirms that the pilots struggled with the automatic trim as it responded to faulty inputs, although they appear not to have activated the cut-out switch for this system.” The “Cut-Out-Switch” is the circuit breaker for the auto-elevator trim.
In the alternative, the pilots can disengage the entire auto-pilot control and simply fly the aircraft manually which is what the controls are for.