A guitar-playing friend who's leaving town for a bit has loaned me the '64 p-bass he inherited from his uncle. It's a player--a bit beat-up, but sounds great, and until four years ago was being gigged regularly. Strings are worn though, and intonation's off. A buddy told me that if I change the strings I'll have to watch out for damage to the neck simply from changing the strings. Is this true? Can I safely change the strings, at least? How about a neck adjustment? Or should I just take it to a luthier and have them give it a set-up and intonation? Obviously, don't want to do any damage to my friend's bass. (He told me to go ahead and fix it up, but I figured I'd check first) Thanks for any input.