OK, so you got the monster real thing and it fits... GOOD.  Too big for me.  The Amazon model fits me better.  Ghurkas are small folks like me.
You can use a regular two grit, gray, hardware carburundum stone, alot of elbow grease and patience.  A fancy sharpener will probably cost more than the knife. (just remembered I carry one of those round, hockey puck shaped, two grit axe stones with mine)
The edge bevel is probably curved, not flat like a chisel, so follow it.  Chops better.  Flat bevel is more precise, but delicate and can chip or roll over.  
You'll like it this knife.  It should serve you well.