Instructions on How to Replace a Pella Slider Window

Remove the original window from the window frame. Remove the sealant that encases the window and pull away the backer rod that sits behind the sealant. Protect your hands and eyes with protective wear. Scrape the sealant from the base of the window with a putty knife but be sure not to damage the home.

Remove the plastic screw covers and unfasten the screws from the installation holes that rest inside the base of the window frame. Pull the window from the frame. Leave the frame jambs and heads in place for the new window. Clean out the window opening to remove any old sealant and adhesive that was left behind. Wipe the opening with a cloth to ensure the area is clean and dry.

Install new sill attachment clips if the old ones are damaged during removal. Set one clip at each end of the sill and one in the center. Drive the clips into the clip grooves with a small hammer. Position the new slider window in the window opening to ensure its proper fit and then remove the window. Line the window opening with sealant that is about ¼-inch thick. Run the sealant around the entire interior of the window opening.

Drill holes in the shims to reuse the installation holes from the previous window. Align the shim with the installation hole in the window opening and mark the hole on the shim with a pencil. Drill a hole into the shim at the indicated point. Repeat the process for all shims.

Set the window in the window opening. Be sure the window rests firmly on the sealant at the center of the window. Place three shims on each side of the window between the window head and window jambs. Drive screws into each installation hole to secure the window in place. Cover each screw with the plastic screw covers that are included with your replacement window.

Seal the window with your foam sealant. Apply the foam backer and finish sealing the window’s perimeter with your exterior grade sealant.