Drag and drop the dxf file in Xtool Creative Space. Here you can make some additional edits, e.g. add some text or change the symbol according to the topic you want to represent with the chest.

In this step, run the two .xcs-Files seperately to get all the parts you need for the chest. I usually engrave with 90% power, 140 mm/s and 140 lines per cm. 
 

In this step you have to assemble and glue the parts together. All the long similar parts belong to the lid, but be careful: there are two different parts, one for the front to have a handle and one for the pack for the hinge. In these cutouts for the hinge the eight small parts with holes in it are glued to be able to connect the top an the bottom via the hinge. 

The hinge ist just the small stick put into the 4 holes on each side and connected to the small circles to keep everything together. The bottom part is just the four walls and any decoration you like to add.
Have fun with the build!