If the engines are started on a legacy Gulfstream (GV models and earlier) with the control lock engaged, it cannot be disengaged without removing Hydraulic power from the controls. The correct way to do this is to shut down the engines and allow the hydraulic pressure to bleed off.
An alternative, non AFM approved method would be to pull the flight power shut off handle which would remove hydraulic power from the flight controls without having to shut down the engines and enable the gust lock to be released.
The big caveat with pulling the flight power shut off handle is that it is only guaranteed to remove hydraulic power from the controls, putting the flight power shut off handle back to its' normal position does not guarantee hydraulic power will be restored to the flight controls.