Generic Mod steps for a MortarAndPestle

1. Open up TestMap.umap in the Ark Dev Kit
2. Create a new folder in Mods (if you don't already have one made for what you are working on) and move the three files you have been working with there (or start them from scratch again like step 3).
3. Create a child (right click > create blueprint based on this) of the following blueprints: PlayerControllerBlueprint, StructurePlacerBlueprint, PrimalGameData_BP, TestGameMode and move each new child you create to your folder in Mods. Easiest way to find these blueprints is to select the Game root folder, and use the right text field (it says Search Game) for the above blueprints.
4. Click Settings > World Settings or go to the panel on the lower right and select World Settings
5. Change Primal Game Data Override to your new PrimalGameData_BP_Child blueprint.
6. Change GameMode Override to your new TestGameMode_Child blueprint.
7. Open PrimalGameData_BP_Child and change Master Item List #107 to be your new PrimalItemStructure_MortarAndPestle_Child and change Engram Blueprint Classes #21 to be your new EngramEntry_MortarAndPestle_Child then compile and save.
8. Open TestGameMode_Child and change Player Controller Class to be your new PlayerControllerBlueprint_Child then compile and save.
9. Open PlayerControllerBlueprint_Child and change Structure Placer Class to be your new StructurePlacerBlueprint_Child then compile and save.
10. Open StructurePlacerBlueprint_Child and add an element to the Placeable Structures list to be your new MortarAndPestle_Child then compile and save.
11. Open EngramEntry_MortarAndPestle_Child and change Blue Print Entry to be your new PrimalItemStructure_MortarAndPestle_Child then compile and save.
12. Open PrimalItemStructure_MortarAndPestle_Child, make any changes you wished to do, change Structure to Build to be your new MortarAndPestle_Child then compile and save.
13. Open MortarAndPestle_Child, make any changes you wished to do, then compile and save.
14. Click Play this level in the active editor view port (if you are loading large maps you will want to instead use the Standalone option) and test if everything works.

To utilize this as a generic mod, create a new level (or copy the GenericMod.umap) in your mod folder. Load that level and ensure it has Global_PostProcess_Blueprint in Scene Outliner. Then ensure that Force Load Map Name is "TheIsland" without quotes (or whatever map you like). Then change Primal Game Data Override in World Settings to be your PrimalGameData_BP_Child blueprint and change Game Mode Override to be your TestGameMode_Child blueprint. Save, click Steam Upload, select the mod folder, specify your umap file without the extension, and cook.