a removable door cassette has a cross member having a lower door frame fixed thereto . the lower door frame has a first frame member fixed to the cross member and a second frame member defining a channel to receive the first frame member . the first frame member is separable from the second frame member . a pivot connection pivotally connects the second frame member to a door housing . a fastener fixedly secures the second frame member in relation to the door housing . a deformable button is preferably used to provide a mechanism to hold the lower door frame into the lower door frame channel and provide a release and locking mechanism between the first and second frame members .