A transformation station for a packaging production machine comprises side frames between which tool-carrier cassettes are mounted. The side frames support slides on which members slide for the mounting of the tool-carrier cassettes. The members for mounting the tool-carrier cassettes comprise cassette supports that can be moved in opposition across and according to material advancing direction dimensions of the tool-carrier cassettes. The cassette supports are fitted with first devices for attaching in position the cassette supports and second devices for locking the tool-carrier cassettes to the supports.