First, confirm the format for your machine. Will your machine stitch out PES designs? No need to work through PES files if they don't work for your machine.
Do you have software on your computer/PC for embroidery files? Usually you would open the "Viking" file in the software. Then "Save as" your machine format extension. I would start a file in computer for converted files. Then transfer the converted file to the USB.
Good luck!