Pry off all of the window's trim from the interior of the house with a pry bar. Insert the end of the pry bar between the window frame and the trim. Push the pry bar downward.
Pry off the molding surrounding the exterior of the window with the pry bar.
Remove the nails along the lip of the window's fins with a claw hammer or pry bar. The fins are located along the exterior edges of the window. The nails secure the window to the house.
Slide the window out of the window's opening to complete the removal.