Using Nokia suite, on a Windows PC I have access to (the machine is not mine), I can download all the messages however they are in vmg format.
I have written a small Erlang module to convert this files to plain text. I might extend this module in the future, for now, it's so small that I'll post it here. The only parameter we need to pass to the exported function, is the path to the folder the vmgs are on. It will loop through every file and create an equivalent txt with the same name in the same place.
%%get all the svg files in the folder
case lists:sublist(FullPath,Length-2,Length) of
"vmg" -> lists:sublist(FullPath,1,Length-3)++"txt";
_ -> ""