Don't let the guys at the shop do it for you. They'll do it in a way that won't make sense. If I am correct, they probably cut the balls off the strings on the neck side and tucked the string in. THAT'S a complicated way to do it. I just thread thru the tuning pegs, leaving the balls. gah, it's easier if you do it than having it written down.

Supposedly, you're supposed to change the strings every 3 months. 6 at most.

Professionals change strings every show.