First you take the surged seam out on the bottom hem about an inch on each side
(2)Cut the surged seam off as close to the seam as you can get( I recommend using fabric scissors as regular paper scissors are not going to cut it-no pun intended)
(3)You can use any fabric/colors you want( as it's your shirt) for this step but I cut purple strips and zigzag stitched them onto a light green fabric rectangle that was 6 inches wide. Make sure the rectangle is a little taller(add about 4 inches) than the side of your shirt.
(4)Line up the edges of the fabric you're adding with the edge of the shirt, pin together and sew.Trim the threads and check for holes. Make sure to sew the hem together on the bottom
(5)And you're done
This shirt had 3 tiny holes and I was going to cut it up for something but since it's such a comfortable shirt I decided against that and instead reversed appliquéd a star with some scrap fabric. Good as new!