First step:
Click resource manager (F10) -> Click Graphic/Tilesets -> Click button Import (pilih file tileset yg tambah).
Second step:
Click database (F9) -> Pilih Tilesets tab -> Pilih category (Field, Exterior, Interior, Dungeon) -> dibagian Graphic, Click drop down kosong bisa C, D or E -> pilih graphic tilesets yg tadi di import.
Click OK atau Apply button... Done...