How how how!?
 
 P.S.::I want to know in the most simplest ways.
  
 
  
  
    Ok, your ganna need a program called notepad :D
 
 look, this is one of Raven's arena files:
 
 
 
 
 {
 map "mp/ffa3"
 longname "Tatooine City"
 bots "Luke"
 fraglimit 10
 type "ffa team"
 }
 
 
 
 Copy it, and add your map specifications. You need the exact map directory path. The longname is what appears in the menu. I dont think the bots or fraglimit matters. For type, you put what game types it is for (ffa team duel ctf... etc. etc...)
 
 save it as your_map.arena then check the file and make sure the name isnt your_map.arena.txt it has to be your_map.arena