Here is a quick demo of the SAMD Loader in action.  It's a pretty straightforward operation:

1) Paperclip or use a RCM clip on the right hand joystick slot

2) Power up SAMD Loader, get a fast blue blink (Looking for USB)

3) Hold Vol + and Power up, blinking will pause for a moment as USB enumerates.

4) Short/Long blink (Ta Daa!) signifies sending and launching the payload

5) Enjoy!

Here I am sending SX Launcher, as I just use my own hekate build stored on SD.  But I have a firmware that sends hekate directly if preferred.  Really, the firmware can be recompiled with any payload you like. To convert a bin file payload to a header for inclusion in the firmware, just use the "bin2header" tool from github to convert.