As stated in previous posts my Tartan 3800 came from Canada. So the MMSI can not be reassigned but must be reset with the US issued MSSI, and that can only be done by the VHF radio manufacturer. It seems the only way to get access to the back of the VHF to remove it is to disassemble the nav station. Before I start ripping my furniture apart and then discover I am going about it wrong, does anyone have knowledge of how to get access to the back of the nav station? It looks like I need to remove the top.