Could someone tell me how to remove corporations from the (new) mod.
Do i do it via XML or with something else. Thanks.

Yes it would be done with XML. In the great people entries in the file Civ4UnitInfos.xml there is a Buildings field. I havent tried it, but removing the corporation options trom this would probably remove the ability to create corporations.

There are also BuildingClass entries for corporations in the file Civ4BuildingInfos.xml. You could change the PrereqTech field so that the corporation never becomes available.