Make a backup of your project before following this guide! And follow the DIY guide linked below before following this guide.
Go to the Blueprints/BuildParts folder and create a new folder called Metal. Then copy the video below.
Next go to the Metal folder you created and rename all the build parts by replacing the word Wood with Metal. Do not change anything else about the name!
Next go to the E_HitboxType and add a new entry by clicking the New button, call the new entry Metal.
Next go to the BuildPartList, here you will need to create a new row for each new metal build part. In the video below is an example of how to do this.
The easiest way is to select the already existing stone rows one at a time and duplicating them so for example duplicate the StoneFoundation row for the metal foundation, StoneWall row for the metal wall and so on, then change the information for the metal build part, don’t for get the MetalWindowBars row, for that one duplicate the WoodWindowBars row as there isn’t a stone windows bar row. You need to do this for all the new metal build parts there are 12 in total one row for each of the build parts in the metal folder you created earlier.
Once you have done this for all the metal build parts, you now need to go though each stone row and change the upgrade build part to the equivalent metal build part row. See the video below for an example.
click save all in your content browser and close the project. Then download and unzip the folder linked below.
Then go to your projects folder, this is the one that has the Content folder in it and copy the video below by copying and pasting the Content folder from the download into the project, it will ask you to replace files this is fine, select to replace the files like the video.
To use the new build parts you must use the hammer to upgrade wood build parts to stone and then to metal. The default resource to upgrade to metal is the iron bars.