How do I transfer my iTunes content on my iPhone to my new 15 MacPro without losing all of it
How do transfer my itunes on my iphone to my new 15 MacPro without losing it.
Honestly, you really don't. If you want all your content on your new computer, copy or move it from the old computer.
It is possible to extract the content from an iOS device, but why expend effort downloading additional software and extracting the data from an iOS device when you can simply copy everything from the old computer?