Originally posted by Havard
Tanone has made an editor to edit adjacent.tbl, but that won't help here since there is no apparant way to "swap the ids" for the HRE.
It actually might work, if you're careful; province 311, for example, would still be in the HRE even though it's now part of the Southern Indian Ocean instead of Magdeburg (which gets the Southern Indian Ocean's old id of 1311).
You'll need to fiddle the map files also, though IIRC Inferis has decoded all the ones with references to province ID.
I wouldn't want to try to actually implement it, though, even if it
does work. If nothing else, debugging would be nightmarish.