If you don't get any answer here there are many knowledgable people over at the Naim forum, or at the pinkfishmedia forum. Maybe the latter forum is better for DIY stuff, the standard answer over at the Naim forum would be 'do not tinker with the holy stuff, let the priests (=the naim dealers) do it'
Thats what I did!
I don't know anything about soldering so I handed mine over to my local dealer for them to perform the soldering as I was buying a pair of bullet plugs from them for the headline at the same time.