I cannot figure out how to remove the shell on the N Scale DD40 models that I have.  I have tried spreading the body at the frame but all this seems to do is to spread just the catwalk and railings.  The shell on this does not seem to come off as it normally does for every other model I own.  Is there something I am missing in trying to remove the body from this model?  Any help is appreciated

I have 3 N Scale DD40AX that I bought around the late 2010's that have DCC but did not have sound at the time.  Is there a board replacement, or some way that I can add sound to these decoders?