Libraries are simply pointers to physical locations, typically defaults are C:\Users\YourUserName (the folders located there) although you can and may have added other locations to your "Libraries".
It is usually a relatively simple matter of copying the contents of, say for instance.....
C:\Users\YourUserName\Music onto an external resource (SD card, USB Thumb Drive, USB external hard disk, etc) and then from there into their respective containers (same place) on your "new one".
Just be mindful of how you handle potential duplicates.