Unlock the window. Atrium window locks are between the upper and lower sash on single- and double-hung windows.
Raise the lower sash three inches. Pull the sash toward you while pushing the tilt latches toward the center of the window. The tilt latches are on both sides of the window frame. Remove the lower sash from the frame.
Lower the upper sash six inches if the window is double-hung. Pull the upper sash toward you while pushing the tilt latches toward the center of the window. Remove the sash from the frame.
Unlock the window. Atrium window locks are between the left and right sashes on horizontal sliding windows.
Slide the window open. On horizontal sliding windows, only the sliding window is detachable.
Slide the anti-lift blocks off the top of the window head. Lift the sash into the head of the window while pulling out the bottom toward you. Remove the sash from the frame.