Method for installing an external trim assembly of a motor vehicle

Method for assembling an exterior trim assembly (13) of a vehicle (10) onto a vehicle structure (15), the trim assembly comprising: - at least one bumper skin (16); - at least one rigid appearance element (18), defining an internal opening (20); - at least one internal trim element (22) intended to be positioned in the internal opening (20) of the appearance element (18); the assembly method comprising: - a step (a) of fixing the internal trim element (22) onto the appearance element (18), - a step (b) of fixing the skin (16) onto the appearance element (18), and - a step (c) of assembling the assembly constituted by the skin (16), the appearance element (18) and the internal trim element (22) onto the structure (15), characterized in that, during steps (a) and (b), the fixing of the internal trim element (22) and of the skin (16) onto the appearance element (18) is performed by respectively abutting the internal trim element (22) against the appearance element (18), and by abutting the skin (16) against the appearance element (18).