1. First Measure the opening of your chimney s clean out opening Second Remove the door from the frame by sliding it up Three Slide the frame into the opening Adjust the tabs so the they fit tightly against the inside sides of the chimney Four Remove the frame from the opening Five Using RTV silicone adhesive chalking Apply the chalking on both the backside of the frame and the face of the chimney around the opening Six Slide the frame back into the opening Using duck tape Tape the frame to the chimney to hold it in place while it dries Wait at least 24 hours before removing the tape and reinstalling the door