I've updated the firmware on my SD4 a couple of times.  The arduino board they refer to is the printer motherboard.  You just plug your printer into your computer like normal.  I've always closed R-H while doing the update, I just assumed it would conflict with the process.

yes it works flawless  now i need to learn how to edit the firmware also..

Selkess, I'd love to hear on this subject too. Can't we assume that Solidoodle updated the firmware on later deliveries since the date on the that firmware version is March (2 months after initial deliveries).

i did the update flashing whit bootloaderhid and works fine  but need recalibrate everything again after

is it possible to update using the guide whit  Lincomatic's BootloaderHID in cmd
and just jumper the board into bootmode whit the same usb cable to my pc ?

or is the only way of updating using a arduino board of some kind?
no one seems to tell right or wrong here.