Use a text editor such as notepad to edit the "UTCustomChar.ini" file in the "/My Games/Unreal Tournament 3/UTGame/Config/" directory. Add the following line at the shoulder pad parts section.

Parts=(Part=PART_ShoPad,ObjectName="CH_Necris_Male1.Mesh.SK_CH_Necris_Male_XShoPad03", PartID="C",FamilyID="NECM")