Help to fit a decoder

[granddad gnome]

Morning all
I am new to DCC, and would like to fit an ESU Lok sound digital + sound decoder into my Bachmann 2-8-0. I have read but not fully understood the booklet that came with the decoder so my question is, Do I need to remove all the fitted wiring and start again from scratch. Your help will be fully appreciated.

Peter (granddad gnome)

 

[ntpntpntp]

Personally, I would say you don't NEED to totally require but some people find it easier and clearer to do this. I've not yet had to totally rewire any of my "complex" locos in order to fit DCC, though some needed a bit of thought and some degree of rewiring (eg. Aristo 66 to cure inherent lighting issues). For me it's been the simple little locos that have needed the full works simply because the wire runs didn't go where I needed them to.