An apparatus for installing a window covering is disclosed. A rotational cam member is provided for extending a first piston on one side of a headrail and compressing a second piston on the opposite side of the headrail between a window casing. A lever arm is provided for rotating the rotational cam. Easy installation of a window covering headrail may be achieved as one arm is used to hold the headrail while the other hand is able to actuated the lever arm. Mounting brackets are provided for easy window covering removal after installation.