If torn, replace it. Otherwise, the most common problem is that stitching dissolves. Every two years or every time I take off the trampoline I take it to a sailmaker or awning shop (or sometimes even a shoe repair) for full 100% re-stitching with teflon thread. Very quick and cheap. When the fist stitching comes free, the rest will follow in minutes. Once completely unstitched in an area then more precision in the repair is often required to keep the critical dimensions that keep it tight (not usually a problem in an old model hobie because of lacing system)