Add the images found in the images folder into your inventory script images folder
Step 5 - Configure
Open up the configuration file and configure. It is very lengthy because it contains the data for the missions. I recommend that you do not mess with any of the mission data, other than stuff like costs, rewards, spawns, ect. You should not be editing stuff like the names of missions, ect, as you will probably break something. It is already pre-configured so you shouldn't have to change much other than what I mentioned above.