Can anyone tell me how to hardwire this decoder in this engine?

How is the boiler shell removed so that a digitrax decoder can be installed?  Any advise or diagrams will be appreciated.  I have installed them in diesels but not in steam engines....Thanks for any help...

What controller is needed to run the dc turnout switches with the e-z controller syster?  I am setting up a new "N" scale system but need info on this DCC controller.....