Arrangement comprising an auxiliary device (1) for changing a knife (16) of a mower with a cutter bar (10) having at least two rotary mowing discs (11) and a knife quick release (12), wherein the knife (16) engages with the knife quick release (12) the mower disk (11) is connected, wherein the knife quick-action closure (12) comprises a flexible component (14) which is designed as a resilient retaining element, characterized in that the auxiliary device (1) brought to the mower disk (11) is adapted to the Messerschnellverschluss (12) drive energy operated for the removal or installation of a knife (16) to open and close again after removal or installation of the blade (16), wherein the drive energy actuated opening and closing operation of the knife quick release (12) by at least an actuator (4) of the auxiliary device (1) is executable, which is adapted to the opening and closing operation of the Messerschnel to perform lverschlusses (12) by displacement of the flexible member (14) in a direction provided.
