Included with SRB2 should've been a file labeled SRB2Src1094.EXE (Or just SRB2Src1094, depending on your system settings.) Double click that. It should make a bunch of folders magically appear. When you start SOCEdit, there should be a box on the left with a list of folders, in that box double-click the one named SRC. SOCEdit should then work.