I still do not understand if you just want to "replace" a category or you want to completely change the EU + sequence.....
To replace even one category you need to edit the speedcam.zip file to see its icon in the menus and on the map. Here I explained a little how to do:
[Only registered and activated users can see links. ]
But if you do not know how to use Illustrator it's impossible to do it.
After the simplest thing is to "trick" both the Dictionary.voice file and the Dictionary.lang.
Spoiler: example
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