Always unmount all Propellers before updating the ESC's.
ESC's without the KISS ESC bootloder may get confused and spin up.
So make sure you have ESC's with it.
KISS24A FW v1.02 or higher: Working bootloader KISS24A FW v1.0 - 1.01: No bootloader KISS 12A, 18A and 30A: No bootloader