Transfer the form and shape of the sunroof you want to replace onto a newspaper by placing and then pressing the newspaper onto the old sunroof. This will help you determine the exact shape and size of the replacement sunroof.
Mark your cut by placing the newspaper pattern from the previous step onto the piece of plywood. As neatly as possible, cut out the plywood using the newspaper pattern as reference.
Attach sheet metal onto the piece of plywood with the help of a clamp. Be sure to make slight indentations on the sheet metal corners.
Give the pattern a close look to ensure everything is in proper order. Make changes if required. Your aim should be to ensure that the sheet metal and piece of plywood are properly affixed to each other.
Get rid of the old sunroof so that the new one can be installed.
Before you actually install the new sunroof, paint the new one but be sure to primer it and then paint it. This will ensure that your paintwork lasts longer.
Carefully position the new sunroof at the appropriate spot and then secure it in place using pop rivets. To prevent water from dripping into the vehicle, it would be wise to apply the goop. Allow time for the goop to dry completely before you move on to the next step.
Finally, check if the area surrounding the sunroof requires painting. If that is the case, paint the desired areas with a colour of your choice.