XexTool has an option -p "patch xex with xexp", maybe this would work?
and then put the patched xex with restrictions removed back in the folder where you launch the game from, also add the files to the respective folder.
or I am talking out of my ass as I have no clue what a xexp is...
actually found a thread in x-s where some people are also talking about thishttp://forums.xbox-scene.com/index.php?showtopic=699896
apparently for some games there are other files that also get patched and this is where it gets non trivial as you can't just overwrite them.