I have jsut done this on my new ECoS and it was quite straightforward.
You only have to download the latest version 1.1.2. You can download it before you connect the ECoS, but do make sure that you download the .BCI version. If you download the .zip version you will have to use something like WinZip to extract it first. Decide where you are going to save the download on your computer as you will need that later.
You will need an ethernet cable to plug into the ECoS and a spare port on your router. The router should assign an IP address to the ECoS automatically. To see the ECoS's IP address follow the instructions i nteh back of the manual. The address will probably start with 192.168. Write down the IP address that the ECoS shows you after you have plugged it in to the router.
You now have to open your internet Browser, i.e. Internet Explorer, and type in the IP address from the ECoS that you wrote down earlier.
You should now see on your PC screen the scereenshot from the back of the ECoS manual. There should be a menu on the left hand side of teh screen. if it's in German, click on the Union Jack for the English translation.
Save teh current settings as it tells you to do i nteh manual.
Now click on the Firmware update button, it really means software update.
You should now see a dialog box and a browse button to the left of it. click o nthe browse button and use the normal process to navigate yoru way to the place on your PC where you stored the BCI download. whic hshould then appear in the dialog box. To start the update click the Send button on your Pc 's screen, and watch the ECoS's screen. DO NOT SWITCH EITHER MACHINE OFF until the ECoS says Update Complete. Then just follow the instructions on the ECoS screen.
I think that's all you need, if I've got any part wrong I hope someone will correct my errors.
Keith.