i feel a tutorial coming on....
create a new folder on your desktop. call it my_faces.
stick the jpg into that folder.
open notepad and copy/paste the following...
class CfgPatches
{
   class my_faces
   {
      units[] = {};
      weapons[] = {};
      requiredVersion = 1.91;
   };
};
class CfgFaces
{
   class bruiser
   {
      name="bruiser";
      texture="\my_faces\bruised.jpg";
      east=1;
      west=1;
   };
};
save that as
config.bin, in the same
my_faces folder.
run pbo utility, find the folder and click create. presto. your addon.
use
this setface "bruiser" to assign the face to a unit.
and if you really
really can't do it, i'll do it for you. but give it a go. face addons are really one of the easiest things to do. try it at least, and if it still doesn't work, come back