you can't edit headshapes with fsh editors. if the patch you're using doesn't have a custom headshape (you'll know that if it doesn't have .ebo files or not) then you don't have to do anything except put the .fsh files in the sgsm folder.
if it does use custom headshapes then find out who's headshape it originally was and export that player's headshape from 06 and use tha for the player you're patching