easy, save the mission go into the mission.sqm in notepad or wordpad and find the civilian you want to change sides for. It helps if you name the guys like west 1, west 2, ect. Find something similar to this. I realize this is a blackop im doing this to, but this is just an example.
position[]={3102.984375,23.419296,6164.833008};
azimut=310.000000;
id=5;
side="WEST";
vehicle="SoldierWSaboteurPipeHGS";
player="PLAYER COMMANDER";
leader=1;
skill=0.600000;
init="this removeweapon ""HK""";
So where it says side="WEST"; put EAST where it would say west on there to make the WEST soldier be recognized as eastern. This works both ways, you can also use it to make any unit resistance or civilian, but i do not recall what those are at the moment. I think resistance is "GUER" but I do not remember. But anyways just save your mission in the editor. Open up the mission.sqm with notepad. Change the side value, save it, then reload your mission in the editor and he will be on that side. But when you die and respawn you will respawn with the default weapon for each side, M16 for the west, and AK47 for the east.