First of all you must NOT interfere with BT's junction box or the wires running from the street to the back back of the Master Socket. You must NOT move or replace the Master Socket, only BT are entitled to do that. Should you do any of the above and cause a problem, BT will charge you a great deal of money to put it right which they are perfectly entitled to do. (They are also entitled in law to take you to court for interfering with their kit.)
The only DIY that you can do is your Internal Wiring (Extension Sockets) from the back of the faceplate of your BT Master Socket. Take wires from connectors 2 & 5 from the back of the Faceplate of the Master Socket to 2 & 5 on the back of the Extension Socket's faceplate. The colour code is Blue & White to 2 and White & Blue to 5. The other wires are spare and should be cut short and tucked out of the way.
T
December 2008