Reply to Firmware upgrade process question

In the tutorial video Ean says remove the harness then connect the firmware kit, but in the video when he puts the kit on the board the harness he pointed out was connected and for the rest of the video its connected.... Leave the harness off for the upgrade?

Is there a certain order I should connect the kit to the board to my PC??

example..

USB to my PC first then connect the serial end to the kit,then attach the kit to the board? Or something else like? kit to board then serial end then usb end??? does it matter?