Create an anchor to your stitch by weaving the needle through the two sides at the start of the tear. Then tie a knot. Repeat this knot 2-3 times for an "anchor". This will keep your sew strong.

Once the anchor is made you can start sewing by looping each side together by weaving the needle through each side of the tear in the fabric and squeeze tight. You should see both sides come together tightly. Repeat this until you reach the end of the tear.