ESP8266 firmware update using espruino pico

Hi,
I try to update the firmware of the ESP8266 like described here using the espruino pico: http://www.espruino.com/ESP8266

I am using 1.80 on the espruino pico. My ESP8622 is soldered. I think I understood the description, but I always get "Failed to connect" with esptool. Since I am not a native speaker this is a litle bit hard to understand:

Take 2 wires and connect one side of each to GND. Connect the first to GPIO0, while connecting and releasing the second to RST

When I do it like I understand a blue LED on the ESP8622 flashes shortly while releasing the wire from RST. Is this correct?

Here is the output of esptool and I am using OSX, if that matters.

{20:16}[1.9.3]~/Downloads/esptool:master­ ✗ ➭ ./esptool.py -p /dev/tty.usbmodem80111 -b 19200 write_flash 0 ESP8266_AT25-SDK112-512k.bin
Connecting...
Traceback (most recent call last):
  File "./esptool.py", line 532, in <module>
    esp.connect()
  File "./esptool.py", line 159, in connect
    raise Exception('Failed to connect')
Exception: Failed to connect

Best regards,
Ben