Ha HA Brilliant...Number One said:I personally take the strings off first. Haven't heard of anyone keeping the strings on while changing the pups. If you keep the strings on, and they vibrate just a little while you're changing pups, it creates an electromagnetic field that heats up the strings to a point where it will snap and rip through your flesh. It'll definitely hurt. That's how Legless Joe lost his arms. So take your strings off.