Unpack the file remesalopolis.scd in the folder gamedata, it can be found under the path:

Steam\steamapps\common\Supreme Commander 2\gamedata

Rules:
1. Spawn Position: Fixed;
2. 8 slot (in the center of the map) - AI: Normal, otherwise map will not work!
3. Exclusions: "Slow Research" and "No Mass Conversion".

It is also recommended to install Lonely Mod, as it removes the engineers at the start.

Installation is the same, just throw the file zz_Lonely.scd and _modsupport_v7.scd in the folder gamedata.

And so you should not play against the usual bots, as they do not go recycle city in the center.

Have fun!