I have an older Enviro M55 Cast Iron Fireplace pellet insert. The daughter board needs to be replaced - it is located to the right of the hopper when you slide the lid open. I have the replacement part, but I can't figure out how to access the daughter board to swap it out. All of the parts around it are riveted. I have seen other posts saying it's simple and to just remove the screws, but mine has no screws, only rivets. I've removed the surround and pulled the stove out but still can't figure out how to access. I don't want to cause damage - is there something easy I am missing? Been searching the internet for tips but everything leads to free standing or newer models that have screws. Just to clarify, I am not talking about the mother board located in the back - that is easily accessible.