A medical sliding-shaft instrument having a first handle arm, a second handle arm pivotably mounted to the first handle arm, a shaft connected to the first handle arm and a slider coupleable to the second handle arm and axially displaceable on the shaft. The slider is removable from the shaft and is guided along a sliding path. A cross-pin couples the second handle arm to the slider and is received in a slot defined by first and second legs of the second handle arm. The first leg is a resilient tongue moveable transversely to a longitudinal axis of the first leg and outwardly away from the second leg. The second handle arm is positioned so that the cross pin lies in the slot. The cross pin is covered and held back by the first leg and is released by applying a force and displacing the end of the first leg.