Re: 1962 shower head
Technically, it is called a shower neck, and yes, you will have to remove it and install a new one with the new head, assuming the new head does not have it's own neck like the existing one does.
Do I need to change the shower bar in the wall to get a new shower head?
In most cases yes, simply unscrew it.
Can I do that without tearing up the wall?
Seeing as how the existing shower head has been in place for 46 years, it might be a bit difficult to remove, you won't know until you try. Using a pipe wrench or channel lock pliers, grab around the base of the neck and turn it counter-clockwise. Once it starts moving, it should unscrew fairly easily. When installing the new neck, wrap the threads with teflon tape, at least 10 wraps and covering all the threaded portion of the new neck. Carefully start the new neck in the hole and turn it clockwise by hand until you can't turn it any more, then using a rag to protect the finish on the neck, use pliers to tighten it snugly. Note: You want the bend in the neck to point downwards, so as you're tightening, pay attention to the position of the neck and how much effort it takes to turn it. DO NOT loosen the neck if you go too far, as this will cause a leak, you will have to make another full turn.
Does the shower bar unscrew in the wall easily?
This is a pretty easy DIY task, give it a shot, if you can't do it yourself, maybe you can borrow a neighbors teenager or husband for a few minutes to help you.
Where is Richard when you need a good plumber and have no husband anymore to help you?
I suffer from CDO ... Its like OCD, but in alphabetical order, LIKE IT SHOULD BE!!!