Measure the window width and height
Decide the curtain rod placement above and beyond the window frame
Mark the bracket positions evenly on both sides
Use a level to keep the marks straight
Drill pilot holes if needed
Install wall anchors if mounting into drywall
Screw the brackets into place
Assemble and extend the curtain rod
Thread the curtains onto the rod or attach hooks/rings
Place the rod onto the brackets
Adjust the curtain panels so they hang evenly
Check that the curtains open and close smoothly
Make final height and fullness adjustments