RCON and Admin

How can I give my friend an admin on the Hamatchi server??? I’ve heard something about the rcon, but I’m not sure. Please help

Oh lord. Well if you absolutely must have that atrocious setup then add him to admins.cfg or yes you can give him your rcon password or better yet add ULX or Evolve admin plugin.

By the sounds of it I’m going to need to explain more though…
Server.cfg
add line rcon_password ReplaceWithYourPW
Give PW
User types “rcon_password pass” in console
User then has rocn
User types “rcon changelevel ttt_minecraft_b5”
etc.