Since no emulator/server was stated, I'll assume you're using the eAthena:
Shops are located in your npc/merchants/shops.txt, once you open it, find the shop you want to edit by using the comments and looking at the NPC name. The shop NPC format goes like this:
Code:
mapname.gat,xcoord,ycoord,direction[tab]shop[tab]NPC Name[tab]NPC Sprite Number,Item1:Price1,Item2:Price2,Item3:Price3
mapname.gatYou can obtain this by typing /where in your chat. An example would be prontera.gat or prt_fild07.gat.
xcoordYou can obtain this by typing /where in your chat. This is basically the horozontal displacement on the map.
ycoordYou can obtain this by typing /where in your chat. This is basically the vertical displacement on the map.
directionYou will need to give the NPC a direction number for the NPC, some NPCs only have 1 or 2 sprites and does not support different directions. If it does, then you should test from a range of 1 - 8 until you have the direction you want it to face. The direction number seems to varie for different NPCs for the same direction.
shopThis should not be changed because it tells eAthena that this is a shop NPC.
NPC NameYou can change this into any name you want but keep in mind there is a character limit and if you go over it, the NPC will have errors.
NPC Sprite NumberThis defines how your NPC looks, to obtain the list, please refer to
this thread.
Item1The item number for the first item sold, you can find this by using the item_db.txt in your db folder or the item_db table in your sql database, their layout is self-explanitory.
Price1The selling price of item1, this should be left at -1 so that it will sell at default price. The only reason you should edit it is if you were selling cards and you don't want them to be sold for 20 zenies.
Other ItemsYou can continue on by adding more items by replacing item2, price2, item3, price3 or you can just have 1 item in your shop. Keep in mind there is a limit to how many items you can display in your shop.
You can also find additional customized NPCs at the official eAthena forums under eAthena DB Release.
You can change job classes in game by using the GM command such as @jobchange [jobnumber].
Ex. Job number 0 is novice, 11 is Knight, 39 is champion.
