To convert a SP map u would need to decompile it, not worth it.
EA released the MP stock maps, DL those and add your spawns and a script for team play.
"all the governments in the world are corrupt and in the hands of the Illuminati"
In that case copy mohdm2.scr and rename it to the name of your BSP and edit the script then place beside the BSP, add some multiplayer spawnpoints to the .map (either via script or Radiant).