I have no way to remove maps from my Zumo 350LM.
I have seen the screenshot on the 4th post of this thread but my Express looks nothing like that? Infact my Express gives me no control whatsoever, can't select regions, can't select use removable storage, can't remove maps.
I tried a new micro SD card but it seems the Southern Europe maps are now in internal memory so the new micro SD made no difference.
I probably shouldn't edit files in the internal memory because that could go badly.
Express is a black box which is fine except when it doesn't work.
I assume Express reads the serial number and knows it's a LM (lifetime maps) model and knows to install full maps without checking my purchase history but that's me guessing.