Caulk secures the window sill edges near the window’s base and the drywall or wood trim on the vertical sides.

How to replace a window sill without removing the window. I demonstrate how to remove a rotten window sill. This allows you to upgrade your window without having to replace the trim and siding. Carefully remove the interior window stool.

To begin the process, you will need to remove the old window sill. The first step for how to replace an interior window sill is using your utility knife to cut the caulk between the window sill and the trim. Replacing the sill is straightforward, but dealing with the underlying reason for the procedure may be complicated.

Home projects often feel daunting because of the cost and time required. To do this you will have to hit the concrete (or timber) with a hammer or with a punch for quite a long time to break it. Using the utility knife, cut the caulk lines.

Under the window trim, measure the distance between the sides. Run caulk around all the exterior stops, and lift the window into place. Remove the old sill and install new sill and sill nose.

The corners should sit flush in the opening. Window stool is usually nailed to the bottom molding and/or sill from the top surface. Next, cut underneath the window sill to free the sill.

Once you've decided to get this done and you have your brand new window sill all good to go, you'd have to first remove the old sill. Dustin shows us how to replace a wood window sill. This is known as a pocket frame window replacement or an insert window.