[rikur]

you'll no doubt get advice from others warning you not to meddle with the installation yourself, breach of T&Cs etc, and a bit difficult to explain if it subsequently goes wrong.

I needed to do a similar mod to my "brown box" in a previous house (C&W fitted it right in the middle of a the bay window so it was the first thing you saw when walking into the room). In my case I found that the other end of the wire (i.e. where the internal telephone socket is) was simply a screw terminal fitting - so I undid the wires at that end (carefully noting which colours were connected where) and threaded the wire back, and then reconnected it.

Alternatively, any decent terminals should do the job for replacing the ones ntl have fitted - but these can suffer a bit over time exposed to the outside damp etc