also my guide is here https://forum.openwrt.org/t/sky-and-dhcp-60-61/39917/13
For me what i did is download wireshark and install.
run wireshark and turn off the sky router and boot back up and you should see the sky Credentials with some searching. Write this password down and save it as you need use it to produce HEX Key found here http://string-functions.com/string-hex.aspx 3 once that is done. copy that and save it.
on my DM200 with open-wrt installed
Log on to the web interface (default ip 192.168.1.1), you may be asked to set a password
Navigate to the "network" tab
Click on the edit button for the wan connection
2.4) Make sure the protocol is set to DHCP Client (click Save and Apply if any changes are made)
Navigate to the "Advanced Options" tab
Add the final key you generated into the Client ID field Thats the HEX Key
Add 6.14.1aN_UNI|PCBAFAST2504Nv1.0 to the Vendor Class field
Click "Save and Apply"
On the WAN Page go to physical setting and add this in the interface drop down box "dsl0.101" save and apply
and all done i had internet.