Take a shortcut when installing new vertical blinds by simply removing the blinds and the headrail and installing the new headrail on the existing brackets. This saves you time and effort in placing and levelling the new brackets, and it can allow you to have your new blinds up in just a few minutes. First you must remove the old blinds and headrail, which is a simple operation.
Close the blinds and twist them open so they are perpendicular to the window.
Remove the valance. Some valances have a series of clips that must be lifted from the top of the headrail, while others simply slide out to one side.
Remove each individual blind from its clip. Some blinds may give with a simple tug, but other clips may be more stubborn. Insert a credit card between the top of the blind and the clip, then pry the clip open until the blind comes free. If you do not plan to reuse the blinds, just break them free of the clips.
Locate the small metal tab at the back of each bracket. Push the tab back while rotating the back of the headrail down. If the metal tab is very small or stubborn, pry it back with a flathead screwdriver.
Rotate the headrail slightly away from you and lift it free of the front side of the bracket. Make sure the back side of the headrail is completely free of the bracket first.
Repeat the process for each bracket. Depending upon the width of the window, there might be up to four.
Longer sets of blinds, like those covering a sliding glass door, may be unwieldy and dangerous to handle by yourself while on a stepladder. An assistant can make things run smoother and more safely.