My sister just dropped off her new Switchback fresh from the pro shop, she wanted me to set it up. The end loop serving is broke on the bottom of the string. I called the shop, they said go ahead and try and fix it and they would just give her a new string the next time she was in town. I've done my own center servings forever, but I've never served an end loop. I don't have a string jig, is there any way I can do this w/out keeping the string taught? If so, what size serving? Anything else I need to know about this? I've got a press and a variety of serving sizes, just haven't ever served an end loop. Thanks for your time.