Save a sample of the broken glass along the edge of the table when possible. Place the glass sample in a Ziploc bag. The glass will inform the glass store of the color, thickness, edging and tempering of the glass.
Tape several sheets of Kraft paper together until you have a sheet that is larger than the table top. Remove any umbrella. Place the paper on a flat floor surface (like a smooth kitchen floor). Invert the table and position the top upside down on the paper and trace around the edge of the table. Measure the size of the table lip for tables that have lips and mark that measurement on the paper. Make your drawing as exact as possible.
Measure the circumference of your umbrella and note this dimension on your Kraft paper drawing. Some glass companies prefer to visit your home and make table measurements themselves. It is important that your measurements be as exact as possible for the table to fit correctly.
Take your drawing and sample to the glass store. Bring any clamps the table uses to push or lock the glass in place, as this may change how the glass company constructs your new top. You will be asked to select your edge work detail, glass tint, thickness and safety type.
Install the new table top. The table top is slid into the metal surround so that it rests on the bottom lip. Spacer lifts or brackets are spaced evenly around the edge of the table to lift the top and press it against the top metal lip. These spacers fit between the bottom lip, outside edge of the table and the underside edge of the glass. Often the lip of the top and bottom edge of the table are slightly different. When possible, ask the glass company to complete the installation for you since thick glass is quite heavy.