hidden tang?
drill a hole the same diameter as the tang
ruff the tang up real well with a file or hacksaw
fill hole in antler with jb weld 2 part epoxy
insert tang into antler orient blade the way you like it and let dry
but thats just how i do it
there are many more qualified people on this site to answer your question with the right way
here,s a pic of 1 i just finished
i hope this helps
kevin