I already tried this..
In the data/roster folder, rename the Japan folder to ' 1 Japan'.
In the data/menu/gui/recmanual folder, rename CovJapan.dds to 'Cov1 Japan.dds'.
In the same folder, rename CovFlagJapan.dds to 'Cov1 FlagJapan.dds'.
(The important thing with these dds files is just to make them match the folder name in data/roster.)
That's it.
Source
http://www.subsim.com/radioroom/show...gnition+manual
But for some reason this name change gives CTD's