If you have OSD info in upper left corner then probably the only thing you lack is GMTbuttons.txt file.
Save this as GMTbuttons.txt in your client folder:
;;
;;Standard devmenu
;;
ONPLAYER,ONNPC;Possess;internal possess
ONPLAYER,ONNPC;Trade;runscript_unsafe dev_menu@unsafe_Trade $[Critter.Id] 0 0
ONITEM,ISCONTAINER;Browse items;runscript_unsafe dev_menu@unsafe_Trade 0 $[Item.Id] 0
ONPLAYER,ONNPC,ISALIVE;Kill;runscript_unsafe dev_menu@unsafe_KillCritter $[Critter.Id] 0 0
ONPLAYER,ONNPC,ISKNOCK;Kill;runscript_unsafe dev_menu@unsafe_KillCritter $[Critter.Id] 0 0
ONCHOSEN,ONPLAYER,ONNPC,ISDEAD;Revive;runscript_unsafe dev_menu@unsafe_KillCritter $[Critter.Id] 0 0
ONNPC;Remove critter;runscript_unsafe dev_menu@unsafe_RemoveCritter $[Critter.Id] 0 0
ONITEM;Remove item;runscript_unsafe dev_menu@unsafe_RemoveItem $[Item.Id] 0 0
ONITEM,ONGROUND;Teleport;runscript_unsafe dev_menu@unsafe_Teleport 0 $[HexX] $[HexY]
ONGROUND,NOHIDE;Airstrike;runscript dev_menu@Airstrike 0 $[HexX] $[HexY]
ONITEM,ISPOSSESS;Pick item;runscript_unsafe dev_menu@unsafe_PickItem $[Possessed.Id] $[Item.Id] 0
ONPLAYER,ONNPC,ISPOSSESS;Attack;runscript_unsafe dev_menu@unsafe_Attack $[Possessed.Id] $[Critter.Id] 0
ONGROUND,ISPOSSESS;Move to;runscript_unsafe dev_menu@unsafe_MoveTo $[Possessed.Id] $[HexX] $[HexY]
ISPOSSESS;Stop;runscript_unsafe dev_menu@unsafe_Stop $[Possessed.Id] 0 0
ONCHOSEN,ONPLAYER,ONNPC,ISKNOCK;Wake;runscript_unsafe dev_menu@unsafe_NeutralizeCritter $[Critter.Id] 0 0
ONCHOSEN,ONPLAYER,ONNPC,ISNTKNOCK;Neutralize;runscript_unsafe dev_menu@unsafe_NeutralizeCritter $[Critter.Id] 0 0