Remove shell from 6-51007 m-10000

Welcome to the forum William. Maybe I can help since I guess I am the only person who has pulled one of these shells. 8 screws on the bottom need removed. 2 of them are behind the front truck so you will have to remove that truck to access  2 of the 8 screws. Front truck is held on with 2 screws. There is also a blue plastic barrier at the end of the loco that will have to be removed. This barrier is held on with 1 screw accessable from sliding your screwdriver downward from the removed roof. I am guessing if all features except sound you probably have an unplugged sound board.  Maybe check your speaker connection. Hope I was able to help. Dont put grandpas pipe smoke fluid in that loco