If you want to import existing runs to your VA3 (from a previous Garmin watch?), it is possible, although they won’t affect your performance stats or totals. (So I’m not sure how useful this is for you.)
If you can get your hands on the original FIT files (*): 1) Use USB cable to connect VA3 to PC. If you have a Mac you need Android File Transfer: https://www.android.com/filetransfer/ 2) Copy FIT files to the \Garmin\activity folder on the watch