The phrase "to replace the window" means to take out the old window and put a new one in its place.
Sentences with «to replace the window»
I love the thought of replacing those windows with doors. (julieblanner.com)
You can however, purchase «full glass» which replaces the windows in your car without a deductible. (accuterm.com)
The cost of replacing windows may seem daunting but consider how much extra money on winter heating and summer cooling you will save with new, fully insulated windows. (remonline.com)