A door handle assembly intended to be mounted on a door of a motor vehicle, said door handle assembly comprising: - a base intended to be fastened on the door, - a handle linked to the base via a hinge at a first end of the handle and via an arm slidably mounted in a housing of the base at a second end of the handle, the handle being movable in rotation relative to the base between a rest position in which it is positioned substantially parallel to the base, the arm being inserted into the housing, and an open position of the door in which it is inclined relative to the base, the arm being partially outside the housing, the arm comprising a hook at one of its ends, - an actuation device housed in the base, intended to be linked to a mechanism for opening the door and comprising a first lever engaging the hook, the first lever being movably mounted in the housing of the base between a retracted position when the handle is in the rest position and a deployed position when the handle is in the open position, the actuation of the handle causing the sliding of the hook of the arm of the handle and of the first lever of the actuation device toward the outside of the base along a sliding axis and the actuation of the door opening mechanism to open the door, the actuation device comprising a return spring exerting a return force on the first lever in order to bring it back toward its retracted position, characterized in that it comprises: - a blocking device movably mounted on the base between an unlocked position in which it does not cooperate with said actuation device and a locked position, when the handle is in the open position, the displacement of the blocking device toward its locked position causing a displacement of the actuation device toward a mounting/dismounting position of the handle in which the first lever of the actuation device is shifted relative to the sliding axis of the arm of the handle causing the blocking of the actuation device, so as to enable the arm of the handle to freely slide within the housing of the base for its mounting in the base or its dismounting from the base. - a base intended to be fastened on the door, - a handle linked to the base via a hinge at a first end of the handle and via an arm slidably mounted in a housing of the base at a second end of the handle, the handle being movable in rotation relative to the base between a rest position in which it is positioned substantially parallel to the base, the arm being inserted into the housing, and an open position of the door in which it is inclined relative to the base, the arm being partially outside the housing, the arm comprising a hook at one of its ends, - an actuation device housed in the base, intended to be linked to a mechanism for opening the door and comprising a first lever engaging the hook, the first lever being movably mounted in the housing of the base between a retracted position when the handle is in the rest position and a deployed position when the handle is in the open position, the actuation of the handle causing the sliding of the hook of the arm of the handle and of the first lever of the actuation device toward the outside of the base along a sliding axis and the actuation of the door opening mechanism to open the door, the actuation device comprising a return spring exerting a return force on the first lever in order to bring it back toward its retracted position, - a blocking device movably mounted on the base between an unlocked position in which it does not cooperate with said actuation device and a locked position, when the handle is in the open position, the displacement of the blocking device toward its locked position causing a displacement of the actuation device toward a mounting/dismounting position of the handle in which the first lever of the actuation device is shifted relative to the sliding axis of the arm of the handle causing the blocking of the actuation device, so as to enable the arm of the handle to freely slide within the housing of the base for its mounting in the base or its dismounting from the base.