The driver-side window on the 2002 Honda Element was shattered by and oncoming car. How would you replace the swinging part of the mirror assembly?
try going to the parts store and buying a chilton manual for the make and model of your vehicle. It has diagrams and step by step instructions. It will cost somewhere around 30 dollars of so and if you ever need to fix any other part of the same vehicle you will have it at your fingertips.
Nearly every muscle in your body is used in swinging a baseball bat. That is assuming the person swinging the bat is doing the conventional "squish the bug, and chop the tree" method to swinging. Simply standing still and swinging the bat would use the muscles in your arms, upper chest, back, and neck muscles.