RV Window Installation Guide Installing a window in your RV is easier than you might think. To make this as easy as possible, we have provided step-by-step instructions for this Do-it-yourself project. Step 1. Prepare the window opening. If you are installing a replacement window you will begin by removing the old window. To do this, remove all the screws around the perimeter of the window frame (inside the vehicle). Once the screws are removed, the window is pushed out of the opening applying force from the inside out. Once the window is out of the hole, you will have to carefully remove any residual sealant that is stuck to the outside wall. If you are installing a window in a new opening, start by tracing the perimeter of the Interior window frame on a piece of cardboard. Tape cardboard template to desired location and trace around template. Remove template and drill holes near each corner with step bit to fit jigsaw blade. Follow along the marked line until cutout is complete. Step 1. Prepare the window opening. If you are installing a replacement window you will begin by removing the old window. To do this, remove all the screws around the perimeter of the window frame (inside the vehicle). Once the screws are removed, the window is pushed out of the opening applying force from the inside out. Once the window is out of the hole, you will have to carefully remove any residual sealant that is stuck to the outside wall. If you are installing a window in a new opening, start by tracing the perimeter of the Interior window frame on a piece of cardboard. Tape cardboard template to desired location and trace around template. Remove template and drill holes near each corner with step bit to fit jigsaw blade. Follow along the marked line until cutout is complete. Step 2. Make sure the window fits. Test fit the new window by simply placing it in the rough opening to ensure a proper fit. The exterior window flange should overlap the opening by 3/8" or more to provide a good seal to the sidewall. A small gap on the inside betwee 1/8"-1/4" is expected and will be covered by the trim ring when the installation is complete. Step 2. Make sure the window fits. Test fit the new window by simply placing it in the rough opening to ensure a proper fit. The exterior window flange should overlap the opening by 3/8" or more to provide a good seal to the sidewall. A small gap on the inside betwee 1/8"-1/4" is expected and will be covered by the trim ring when the installation is complete. Step 3. Prepare and install sealant Lay the new window face down on a soft surface careful not to scratch it and apply seal if it is not provided. Start in the center of the bottom side of the window and apply the seal tape flush all the way around the perimeter until the ends meet (Note: There should not be a gap where the seal ends meet). As Picture 1 Place the window into the opening from outside the vehicle, while a second person aligns the trim ring holes to the channel on the interior side of the window. (Note: When installing a horizontal window, the stationary window should face towards the front of trailer and weep hole plugs should only be removed on the bottom.) As Picture 2 Begin fastening the trim ring with the provided screws, starting with the 4 corners first. Work your way around the perimeter gradually tightening each screw as you go. This will gently pull the trim ring and window together. (Note: Use only the screws provided with the new window, as longer screws could damage the window frame). As Picture 3 Useful tips: Use a spray water bottle and mist the perimeter of the opening on the outside of the vehicle.This is done to prevent the tape from sticking to the outside wall before you are satisfied with the final position of the window.It is often easier to handle a window if the sliding glass is in the open position.Remove the window screen during installation to prevent it from being damaged and to make it easier to handle the window.Make certain to use the screws provided with your windows for installation. Use of longer screws can puncture the window frame and be a source for a potential leak. Useful tips: Use a spray water bottle and mist the perimeter of the opening on the outside of the vehicle.This is done to prevent the tape from sticking to the outside wall before you are satisfied with the final position of the window.It is often easier to handle a window if the sliding glass is in the open position.Remove the window screen during installation to prevent it from being damaged and to make it easier to handle the window.Make certain to use the screws provided with your windows for installation. Use of longer screws can puncture the window frame and be a source for a potential leak.